Fixes orientation changes for Android Tablets.
Fix for orientation when Activity closed.

Android Activity still lives, so the OnOrientationChanged event is still
executed, even thou AndroidGameActivity.Game is null. This commit fixes
this issue. Since it's a very small fix and related to the same method
of the first commit, I just added another commit to the same PR.
Merge pull request #1987 from azchohfi/androidOrientationFixForTablets

Fixes orientation changes for Android Tablets.
Fix potential framebuffer corruption on iOS

Remove unnecessary call in DestroyFramebuffer that can cause framebuffer corruption if a user framebuffer is bound when called.
Merge pull request #2014 from flyingdevelopmentstudio/IOSGameView-fix

Fix potential framebuffer corruption on iOS
Added solution & project for Windows OpenGL tests
VertexElementColor R,G,B,A properties must be public.

I am not really sure what is the purpose of VertexElementColor in
VertexPositionColor.
XNA documentation states that it should have been a 'Color'. Also one
should be able to define it's own IVertex structure and they would
normally use a 'Color' to do so.

What I see is that Color defines Getter/Setter for storing those values
into a packed int. Is this really necessary? A struct is a struct after
all. Same effect could have been achieved with StructLayout/FieldOffset
attributes.

Anyways. For now R/B/G/A properties must be publicly accessible as they
are on 'Color'.
Remove VertexElementColor struct

Remove Remove VertexElementColor struct and replace it with Color in
VertexPositionColor.
Merge pull request #2022 from nkast/nKast

Remove VertexElementColor struct
Merge pull request #2015 from MichaelDePiazzi/windowsgl-tests

Added solution & project for Windows OpenGL tests
Move GraphicsDevice property from GameComponent to DrawableGameComponent

 to

GameComponent exposes a public GraphicsDevice property which is not
available on XNA. This property belong to DrawableGameComponent.

https://github.com/mono/MonoGame/issues/1807#issuecomment-19672898

This fix was posted by @Aztherion together with a
DynamicSoundEffectInstance  implementation but merge has been postponed
since then. I am posting a clean fix to this issue.
Merge pull request #2027 from nkast/nKast

Move GraphicsDevice property from GameComponent to DrawableGameComponent
Merge branch 'develop' into stable_BtA