FNA Code Style ./P* - R*

Flibitized.  Removed unnecessary parenthesis from commutative additions.
Format fixes.

This fixes the items Flibitijibibo noted, and a couple of whitespacing issues
that MonoDevelop slipped into the code.
FNA Code Style Cleanup
Fix bizarre tabbing in licensing.
Simplify operator overloads
Merge pull request #188 from 3vi1/monogame-sdl2

FNA Code Style ./I* - R*
Supplement to 3vi1 FNA fixes
Generic whitespace cleanup
SDL2_GamePad whitespace cleanup
Yet another pass through Matrix.cs
Remove unused method
Lots of weird spaces in the math files...
Eep, that could have ended poorly
Remove redundant import.

This eliminates three warnings about Microsoft.targets.csharp already
having been imported when building FNA.
Merge pull request #189 from 3vi1/monogame-sdl2

Remove redundant import.
Remove non-SDL2 project files from Lidgren.Network.SDL2
Merge pull request #190 from 3vi1/monogame-sdl2

Remove non-SDL2 project files from Lidgren.Network.SDL2