==== Changes Related to manifests ====

* Add the `manifests` feature flag
  * This only says whether we look for a `vcpkg.json` in the cwd, not
    whether we support parsing manifests (for ports, for example)
* Changes to the manifests RFC
  * `"authors"` -> `"maintainers"`
  * `--x-classic-mode` -> `-manifests` \in `vcpkg_feature_flags`
  * reserve `"core"` in addition to `"default"`, since that's already
    reserved for features
  * Add a small helper note about what identifiers must look like
  * `<license-string>`: SPDX v3.8 -> v3.9
  * `"feature"."description"` is allowed to be an array of strings as well
  * `"version"` -> `"version-string"` for forward-compat with versions
    RFC
* Add the `--feature-flags` option
* Add the ability to turn off feature flags via passing
  `-<feature-flag>` to `VCPKG_FEATURE_FLAGS` or `--feature-flags`
* Add CMake toolchain support for manifests
  * Requires either:
    * a feature flag of `manifests` in either `Env{VCPKG_FEATURE_FLAGS}`
      or `VCPKG_FEATURE_FLAGS`
    * Passing the `VCPKG_ENABLE_MANIFESTS` option
  * The toolchain will install your packages to
    `${VCPKG_MANIFEST_DIR}/vcpkg_installed`.
* Add MSBuild `vcpkg integrate install` support for manifests
  * Requires `VcpkgEnableManifest` to be true
* `vcpkg create` creates a port that has a `vcpkg.json` instead of a
  `CONTROL`
* argparse, abseil, 3fd, and avisynthplus ports switched to manifest
  from CONTROL
* Add support for `--x-manifest-root`, as well as code for finding it if
  not passed
* Add support for parsing manifests!
* Add a filesystem lock!

==== Important Changes which are somewhat unrelated to manifests ====

* Rename `logicexpression.{h,cpp}` to `platform-expression.{h,cpp}`
* Add `PlatformExpression` type which takes the place of the old logic
  expression
  * Split the parsing of platform expressions from checking whether
    they're true or not
  * Eagerly parse PlatformExpressions as opposed to leaving them as
    strings
* Add checking for feature flag consistency
  * i.e., if `-binarycaching` is passed, you shouldn't be passing
    `--binarysource`
* Add the `Json::Reader` type which, with the help of user-defined
  visitors, converts JSON to your internal type
* VcpkgArgParser: place the switch names into a constant as opposed to
  using magic constants
  * In general update the parsing code so that this ^ works
* Add `Port-Version` fields to CONTROL files
  * This replaces the existing practice of
    `Version: <my-version>-<port-version>`

==== Smaller changes ====
* small drive-by cleanups to some CMake
  * `${_VCPKG_INSTALLED_DIR}/${VCPKG_TARGET_TRIPLET}` ->
    `${CURRENT_INSTALLED_DIR}`
  * Remove `-analyze` when compiling with clang-cl, since that's not a
    supported flag (vcpkg's build system)
  * Add a message about which compiler is detected by vcpkg's build
    system machinery
* Fix `Expected::then`
* Convert `""` to `{}` for `std::string` and `fs::path`, to avoid a
  `strlen` (additionally, `.empty()` instead of `== ""`, and `.clear()`)
* Add `Strings::strto` which converts strings to numeric types
* Support built-in arrays and `StringView` for `Strings::join`
* Add `operator<` and friends to `StringView`
* Add `substr` to `StringView`
* SourceParagraphParser gets some new errors

* [abseil] Enable dynamic build on Windows

* re-fix arm build

* [abseil] Fix arm build

* update baseline

Adds a patch changing macros in absl/base/options.h to
always use the std:: namespace types instead of the
absl:: namespace replacements (for any, optional,
string_view, variant).
The upstream version of options.h uses compiler/library
feature detection to decide this, but patch
fix-lnk2019-error.patch hard codes use of absl:: types,
thus rendering setting CMAKE_CXX_STANDARD to 17 in the
port file ineffective. Since auto detection is problematic
from an ABI point of view (see comments in
absl/base/options.h for details), this applies an
alternate patch for fix-lnk2019-error.patch when feature
cxx17 is enabled.

* [abseil] Fix CompressedTuple move constructor on MSVC

* [abseil] Add comment for new patch

* [abseil] Add compiler C++17.

* Add feature c++17.

* [abseil] Add uwp support

* [abseil] Drop support with arm/arm64

* [opencensus-cpp] Add keyword supports

* update baseline

* [abseil] Enable arm support

* remove unfinished "supports" tag

* extract "supports" from control files
But do nothing with the value

* Start `Supports` documentation

* Use Supports in a bunch of control files

I only tried matching the already existing logic in the portfile.cmake.

* Cmake var provider (#8)

* Cmake var provider (#9)

* fix windows build (#10)

* Add missing files to build

* Fix test (#11)

* adding hooks for cmake variables in expressions

* Adding hooks for 'supports' in CI test

* Fix test (#12)

* Add overrides to evaluation environment

* use "supported" tag in CI testing

* cleanup comment

* Fix issues with PR

* [var_provider] Get library linkage variables from triplet

* Fix compilation errors in tests

* Add unimplemented functions

* Fix unit tests part 1

* Fix issue when buildtrees dir does not exist

* Change binary output hash

* Fix handling of * feature

* Add core feature when using *

* Do not add Default-Features when installing 'core'

* [vcpkg] WIP. 6 failing tests.

* [vcpkg] WIP. 1 failing tests.

* [vcpkg] WIP. 0 failing tests.

* [vcpkg] Removed 'remove_graph'. 0 failing tests.

* [vcpkg] Removed 'install_graph'. 0 failing tests.

* [vcpkg] Remove AnyAction; replace with ActionPlan

* [vcpkg] Minor cleanup.

* [vcpkg][z3][qt5-connectivity][qt5-purchasing] Improve error messages while parsing. Fix a few trivial port issues.

* [vcpkg] Work around ICE with MSVC v140

* [vcpkg] Add purge on fail to decompress for CI

* [vcpkg] Fix parsing of nested parentheses in qualifiers

* [vcpkg] Fix Linux builds (explicit qualification in declaration)

* [vcpkg] Fix Build-Depends implying default features. Fix qualified dependencies regression.

* [mmx] Add to skip list and full rebuild -- mmx causes problems by installing 'sched.h'

* [libpqxx][mqtt-cpp] Prevent installing include/CMakeLists.txt

* [cppitertools] Fix installed include namespace (should be include/cppitertools)

* [libsoundio] Move headers into soundio/ subdirectory as per original cmake

* [ci.baseline] Temporarily skip charls due to conflict with dcmtk

* [vcpkg] Add restricted include files post build check -- bump global abi version

* [libsoundio] Hotfix stray line in portfile

* [vcpkg] Fix regression: CMake information was not being displayed for build-and-install actions

* [jsonnet] Fix installation of internal headers; use system nlohmann-json

* [grpc][upb] Teach grpc to use packaged upb. Add find_package(upb). Remove inappropriate upb features.

* [zfp] Move problematic 'include/bitstream.h' to 'include/zfp/bitstream.h'

* [x265] Bump control version to trigger rebuild after zfp conflict

* [akali] Disable parallel configure

* [dirent][dlfcn-win32][getopt-win32][pthreads] Grandfather into VCPKG_POLICY_ALLOW_RESTRICTED_HEADERS

* [ci.baseline] Update baseline for improved upb support

* [tgui] Disable parallel configure

* [libiconv] Enable VCPKG_POLICY_ALLOW_RESTRICTED_HEADERS

* [aws-sdk-cpp] Disable parallel configure

* [vcpkg] Implement policy VCPKG_POLICY_ALLOW_RESTRICTED_HEADERS

* [aws-sdk-cpp] Fix amount of escaping semicolons -- Note: I do not know the root cause requiring this change

* [libodb-sqlite] Fix configuring into source directory

* [gettext] Grandfather into VCPKG_POLICY_ALLOW_RESTRICTED_HEADERS

* [libodb] DISABLE_PARALLEL_CONFIGURE

* [vcpkg] Add 'config.h' and 'local.h' to restricted header list

* [mcpp] Remove unused and problematic include 'config.h' from installed files

* [teemo] Move installed headers into subdirectory to prevent conflicts with x265

* [ci.baseline] Update current OSX. Skip libmesh on all platforms due to heavy conflicts.

* [vcpkg] Add 'slice.h' as a restricted header

* [osg] Improve accuracy of dependencies (disable some, add some to Depends)

* [vcpkg] Skip invoking a subprocess for 0 specs in load_tag_vars

* [ci.baseline] Skip mongo-c-driver on osx due to flakiness

* [teemo] Fix incorrect include file read

* [osg] Fix dependency typo: glut -> freeglut

* [vcpkg] Recover some lost performance with the addition of vcpkg_get_tags.

A huge performance cost was loading the triplet files over and over; instead, we splice the sources into a macro and load it once, then just call that macro for each port.
Remove use of hashing because we aren't cross-process-safe anyway (global static will do instead).

* [vcpkg] Change Supports atom 'windows' to include UWP. Improve Supports field documentation.

* [vcpkg] Add docs for VCPKG_ENV_PASSTHROUGH and VCPKG_DEP_INFO_OVERRIDE_VARS

* Fix typo

Co-authored-by: Curtis J Bezault <curtbezault@gmail.com>
Co-authored-by: Victor Romero <romerosanchezv@gmail.com>
Co-authored-by: Robert Schumacher <roschuma@microsoft.com>