* [vcpkg] Consolidate several internal parsers together (packagespecs + logicexpression + control) and enhance error messages

* [vcpkg] Migrate Build-Depends parsing to new framework

* [vcpkg] Fix tests. Re-enable underscores in feature names due to libwebp[vwebp_sdl] -- todo: rename this feature and remove underscores.

* 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>

- Add the "VCPKG_DEVELOPMENT_WARNINGS" flag
	- setting "WERROR" will also set this flag
	- This flag is set by default
	- on GCC/clang, this will pass '-Wall -Wextra -Wpedantic -Werror'
	- on GCC, this will additionally pass '-Wmissing-declarations'
	- on clang, this will additionally pass '-Wmissing-prototypes'
	- on MSVC, this will pass '-W4 -WX'
- On Visual Studio 2017 and later, pass '-permissive-'
- Change the source for fallout of these changes
- add `format` subcommand
	- formats all C++ source and header files using clang-format
- move `include/vcpkg-test/catch.h` to `include/catch2/catch.hpp`
- pass CONFIGURE_DEPENDS to file(GLOB)

I added benchmarks to measure how fast the parallel remove_all code was
-- it turns out, about 3x slower than stdfs::remove_all. Since this was
the case, I removed all of the parallelism and rewrote it serially, and
ended up about 30% faster than stdfs::remove_all (in addition to
supporting symlinks).

In addition, I did the following three orthogonal changes:
  - simplified the work queue, basing it on Billy O'Neal's idea
  - Fix warnings on older versions of compilers in tests, by splitting
    the pragmas out of pch.h.
  - Ran clang-format on some files

In fixing up remove_all, the following changes were made:
  - On Windows, regular symlinks and directory symlinks are distinct;
    as an example, to remove directory symlinks (and junctions, for that
    matter), one must use RemoveDirectory. Only on Windows, I added new
    `file_type` and `file_status` types, with `file_type` including a new
    `directory_symlink` enumerator, and `file_status` being exactly the
    same as the old one except using the new `file_type`. On Unix, I
    didn't make that change since they don't make a distinction.
  - I added new `symlink_status` and `status` functions which use the
    new `file_status` on Windows.
  - I made `Filesystem::exists` call `fs::exists(status(p))`, as opposed
    to the old version which called `stdfs::exists` directly.
  - Added benchmarks to `vcpkg-test/files.cpp`. They test the
    performance of `remove_all` on small directories (~20 files), with
    symlinks and without, and on large directories (~2000 files), with
    symlinks and without.