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, 35 insertions, 12 deletions

diff --git a/ports/skia/CONTROL b/ports/skia/CONTROL
deleted file mode 100644
index e06605d1d..000000000
--- a/ports/skia/CONTROL
+++ /dev/null
@@ -1,12 +0,0 @@
-Source: skia
-Version: 2020-05-18
-Port-Version: 4
-Homepage: https://skia.org
-Description: Skia is an open source 2D graphics library which provides common APIs that work across a variety of hardware and software platforms.
-  It serves as the graphics engine for Google Chrome and Chrome OS, Android, Mozilla Firefox and Firefox OS, and many other products.
-  Skia is sponsored and managed by Google, but is available for use by anyone under the BSD Free Software License. While engineering of the core components is done by the Skia development team, we consider contributions from any source.
-Supports: x64 & (osx | windows)
-Build-Depends: expat, freetype[core], icu, harfbuzz[icu], libjpeg-turbo, libpng, libwebp, zlib
-
-Feature: metal
-Description: metal support for skia
diff --git a/ports/skia/vcpkg.json b/ports/skia/vcpkg.json
new file mode 100644
index 000000000..46bcc003f
--- /dev/null
+++ b/ports/skia/vcpkg.json
@@ -0,0 +1,35 @@
+{
+  "name": "skia",
+  "version-string": "2020-05-18",
+  "port-version": 5,
+  "description": [
+    "Skia is an open source 2D graphics library which provides common APIs that work across a variety of hardware and software platforms.",
+    "It serves as the graphics engine for Google Chrome and Chrome OS, Android, Mozilla Firefox and Firefox OS, and many other products.",
+    "Skia is sponsored and managed by Google, but is available for use by anyone under the BSD Free Software License. While engineering of the core components is done by the Skia development team, we consider contributions from any source."
+  ],
+  "homepage": "https://skia.org",
+  "supports": "x64 & (osx | windows)",
+  "dependencies": [
+    "expat",
+    {
+      "name": "freetype",
+      "default-features": false
+    },
+    {
+      "name": "harfbuzz",
+      "features": [
+        "icu"
+      ]
+    },
+    "icu",
+    "libjpeg-turbo",
+    "libpng",
+    "libwebp",
+    "zlib"
+  ],
+  "features": {
+    "metal": {
+      "description": "metal support for skia"
+    }
+  }
+}