Merge pull request #182 from extrahotchilipowder/monogame-sdl2

[FNA] #147 cleanup and tabifying of remaining Graphics/ files
Additional Graphics/ cleanup
Goddamnit Joe
Generic spacing cleanup
Fix += from Joe cleanup
A few increments...
Minor Content*Manager changes
I wonder how GDI+ does this...
Why was that overload there...?
Texture2D region ordering
Remove OpenTK using statement