Removed old shader files.
Fixed shader format to write the shader code length as 32bit integer.
Incremented MGFX version to 5.
Rebuilt stock effects to MGFX version 5.
Fixed SamplerStateCollection to reset to SamplerState.LinearWrap.
Sharing the sampler initialization with Clear().
Merge pull request #1541 from SickheadGames/samplerfix

Fixed SamplerStateCollection to reset to SamplerState.LinearWrap
Merge pull request #1531 from SickheadGames/mgfx

MGFX Large Shader Fix
Sprite should have default origin at the center
Merge remote-tracking branch 'remotes/origin/develop3d' into develop3d
Merge remote-tracking branch 'remotes/upstream/develop' into develop3d