Fix origin transform in DrawInternal with src rect

This change fixes a transform applied on the origin parameter
passed to DrawInternal, based on the ratio between the destination
rectangle and the texture width / height.

When a source rectangle has been specified, its size should be used
instead.
Fix edge-case when source rect has 0 width/height

Nothing would get rendered when the source rectangle had a width or
height of zero, whereas XNA does render something.
Merge branch 'develop3d' of https://github.com/mono/MonoGame into develop3d
Merge branch 'develop3d' into FontProcessor
Merge branch 'develop3d' of https://github.com/mono/MonoGame into develop3d
Implemented ResizePowerOfTwo.
Update MonoGame.Framework/Graphics/Effect/EffectParameter.cs

I needed to implement GetValueMatrix() for a project so I'm adding my minor work as a pull request.
Implemented ColorKeyEnabled.
Merge pull request #1248 from puargs/patch-1

Implement Graphics.Effect.EffectParameter.GetValueMatrix()
Merge pull request #1247 from SickheadGames/ResizePoT

Implemented ResizePowerOfTwo
Removed miscomitted test value.
Fixed premultiplied alpha. Removed GraphicsUtil.PremultiplyAlpha().
Added events for KeyUp and KeyDown

The KeyUp and KeyDown methods are very important for low level keyboard
access but in MonoGame the general solution of overriding the view
cannot be done so I expose both as events.
Merge pull request #1249 from SickheadGames/ColorKeyEnabled

Implemented chroma keying
Suppport for all Bitmap PixelFormats.
Merge branch 'PremultiplyAlpha' into MorePixelFormats
Rebase off of PremultiplyAlpha.
Merge pull request #1252 from SickheadGames/PremultiplyAlpha

Fix for Premultiply Alpha.
Merge branch 'develop3d' into MorePixelFormats
Merge pull request #1253 from SickheadGames/MorePixelFormats

Support for all PixelFormats