-added Vignette PostFx

-added vignette to the Full and Empty Template
-added vignette to the PostEffect Manager
-added vignette Shader and .cs File
Enable RGB format for DDS files getting copied to bitmap.
Terrain baseTex support multiple formats
DDS, PNG, JPG or NONE
Expose new formats to the editor.
Merge pull request #761 from J0linar/PostFx_Vignette

Added Vignette PostFx
Reduce minimum tab width in PostFX manager.
Merge pull request #886 from eightyeight/fix-postfx-manager

Reduce minimum tab width in PostFX manager
Merge pull request #793 from lukaspj/Terrain-Basetex-Formats

Terrain basetex formats