Removing [Flags] From the Keys.cs enum.
Merge pull request #1943 from nightst4r/Enum_FlagRemove

Removing [Flags] From the Keys.cs enum.
Disabled those windows touch helpers (like the press & hold context box).
Fix Texture2D PVRTC size computation
Fix for game init when running under unit test runner
Merge pull request #1950 from SickheadGames/wintouchfix

Disabled Windows Touch Helpers
Merge pull request #1953 from flyingdevelopmentstudio/Texture2D-fix

Fix Texture2D PVRTC size computation
Merge pull request #1958 from DaveEmmerson/unit-test-fixes

Fix for game init when running under unit test runner
Merge branch 'develop' of git://github.com/mono/MonoGame into monogame-sdl2