Added ResumeManager so something can be drawn whilst textures are being reloaded.

*How it works*
The textures are now reloaded on a different thread so execution can continue. The AndroidGameWindow._isResuming is set so the optional IResumeManager can be drawn. A default ResumeManager implementation has been provided so users can easily set it up with a custom texture rotating in the middle of the screen.

*Motivation*
Reloading of textures can take a LONG time. Whilst this occurs the user is presented with a black screen and the music playing. This leads to confusion about whether the game may have crashed. Also, when adding full screen ads to a game, these generally cause the GL context to be lost so when the user dismisses the ad, they are hit with this lengthy texture reload each time.
Convert default ResumeManager to use a ContentManager instead of Texture2D.FromStream
WIP fixes to FontDescriptionProcessor.
Merge branch 'FontProcessor' of https://github.com/SickheadGames/MonoGame into FontProcessor
Merge branch 'develop3d' into FontProcessor

Conflicts:
	MonoGame.Framework.Content.Pipeline/MonoGame.Framework.Content.Pipeline.Windows.csproj
Merge branch 'develop3d' into FontProcessor
[All platforms]: Window.IsBorderless feature

new feature
[WinDX]: IsMouseVisible + IsBorderless

code for IsMouseVisible and IsBorderless properties
[WinDX]: Clean up

Now hides the cursor by default (XNA does this).
Fixed bad #if in templates.
Added Windows desktop DirectX template for VS.
Fixed installer script to include Windows desktop DirectX.
Merge branch 'FontProcessor' of https://github.com/SickheadGames/MonoGame into FontProcessor
Merge develop3d in resume_manager

Fixed one merge conflict in Adroid csproj
Merge branch 'develop3d' into resume_manager
Merged actual latest develop3d into resume_manager
Replaced NSTimer with CADisplayLink.
Changed Tick() from public to internal.
[WinGL/Linux]: Window.Borderless feature

new feature
[All platforms]: GameWindow comment rename