Bulk convert control files. (#19986)

```
function Convert-Control {
    Param($full)
    .\vcpkg.exe format-manifest $full
    $root = $full.Substring(0, $full.Length - 7) # CONTROL
    $new = $root + 'vcpkg.json'
    $content = Get-Content -Raw $new
    $asJson = ConvertFrom-Json $content -AsHashtable -Depth 100
    $oldVersion = $asJson['port-version']
    if ($null -eq $oldVersion) {
        $oldVersionFull = $asJson['version-string']
        Write-Host "Got version $oldVersionFull"
        $match = [System.Text.RegularExpressions.Regex]::Match($oldVersionFull, '^(.+)-(\d+)$')
        if ($match.Success -and -not [System.Text.RegularExpressions.Regex]::IsMatch($oldVersionFull, '^\d\d\d\d-\d\d-\d\d$')) {
            $newFullVersion = [string]$match.Groups[1].Value
            $oldVersion = [int]$match.Groups[2].Value
            Write-Host "newFullVersion $newFullVersion oldVersion $oldVersion"
            $newVersion = $oldVersion + 1
            $asJson['version-string'] = $newFullVersion
            Write-Host "Previous version for $full extracted from version field -- setting version-string $newFullVersion and port-version $newVersion"
        } else {
            Write-Host "No previous version for $full -- setting 1"
            $newVersion = 1
        }
    } else {
        $newVersion = [int]$oldVersion + 1
        Write-Host "New version for $full : $newVersion"
    }

    $asJson['port-version'] = $newVersion

    $content = ConvertTo-Json $asJson -Depth 100
    Set-Content -Path $new -Value $content
    .\vcpkg.exe format-manifest $new
}

Get-ChildItem ports\CONTROL -Recurse | Foreach-Object {
    Convert-Control $_.FullName
}

git commit -am "this message"
.\vcpkg.exe x-add-version -all
git commit -a --amend
```

2 files changed, 30 insertions, 7 deletions

diff --git a/ports/azmq/CONTROL b/ports/azmq/CONTROL
deleted file mode 100644
index 8d29c6d03..000000000
--- a/ports/azmq/CONTROL
+++ /dev/null
@@ -1,7 +0,0 @@
-Source: azmq
-Version: 2020-03-03
-Build-Depends: boost-asio, boost-assert, boost-config, boost-container, boost-format, boost-intrusive, boost-iterator, boost-lexical-cast, boost-logic, boost-optional, boost-random, boost-range, boost-regex, boost-system, boost-thread, boost-utility, zeromq
-Homepage: https://github.com/zeromq/azmq
-Description: Boost Asio style bindings for ZeroMQ
-  This library is built on top of ZeroMQ's standard C interface and is intended to work well with C++ applications which use the Boost libraries in general, and Asio in particular.
-  The main abstraction exposed by the library is azmq::socket which provides an Asio style socket interface to the underlying zeromq socket and interfaces with Asio's io_service(). The socket implementation participates in the io_service's reactor for asynchronous IO and may be freely mixed with other Asio socket types (raw TCP/UDP/Serial/etc.).
diff --git a/ports/azmq/vcpkg.json b/ports/azmq/vcpkg.json
new file mode 100644
index 000000000..6344423fa
--- /dev/null
+++ b/ports/azmq/vcpkg.json
@@ -0,0 +1,30 @@
+{
+  "name": "azmq",
+  "version-string": "2020-03-03",
+  "port-version": 1,
+  "description": [
+    "Boost Asio style bindings for ZeroMQ",
+    "This library is built on top of ZeroMQ's standard C interface and is intended to work well with C++ applications which use the Boost libraries in general, and Asio in particular.",
+    "The main abstraction exposed by the library is azmq::socket which provides an Asio style socket interface to the underlying zeromq socket and interfaces with Asio's io_service(). The socket implementation participates in the io_service's reactor for asynchronous IO and may be freely mixed with other Asio socket types (raw TCP/UDP/Serial/etc.)."
+  ],
+  "homepage": "https://github.com/zeromq/azmq",
+  "dependencies": [
+    "boost-asio",
+    "boost-assert",
+    "boost-config",
+    "boost-container",
+    "boost-format",
+    "boost-intrusive",
+    "boost-iterator",
+    "boost-lexical-cast",
+    "boost-logic",
+    "boost-optional",
+    "boost-random",
+    "boost-range",
+    "boost-regex",
+    "boost-system",
+    "boost-thread",
+    "boost-utility",
+    "zeromq"
+  ]
+}