Merge pull request #199 from 3vi1/monogame-sdl2

Removed Unnecessary Using Directives.
Add missing CheckGLError and whitespace tidy up this block. Fixes #1878
Merge pull request #2373 from danzel/fix-1878

Add missing CheckGLError
Remove MonoLive/MonoLiveClient and entries in protobuild. Fixes #1519
Merge pull request #2374 from danzel/fix-1519

Remove MonoLive/MonoLiveClient and entries in protobuild.
Correct handling of WeakReference so they are correctly removed from the list. Fixes #1991
Set _selfReference to null after removing it from the collection
Merge pull request #2375 from danzel/fix-1991

Correct handling of WeakReference so they are correctly removed from the list
IsConnected fix

Will no longer return true if an exception occurs creating the
DriveInfo object on Windows.
Optimize the VideoPlayer OpenGL work. Still has a glGet :(
Only need one tab, we get it.
Merge back from develop
Merge pull request #201 from 3vi1/monogame-sdl2

Storage Comment Cleanup
Merge pull request #202 from 3vi1/storage-fix

IsConnected fix