Remove RGB8 fallback format from RGB555 to prevent test failure in FNDDRAW utility. Add a fallback format for RGBA1555.
Remove RGB8 fallback format from RGB555 to prevent test failure in FNDDRAW utility.
Add a fallback format for RGBA1555.


git-svn-id: 763a368b42d23a8c112339c16f7e9c1b0ab7c9a5@478 8a90861a-4eca-46d5-b744-240ff16d0c4d

WilliamFeely/dxgl,WilliamFeely/dxgl,WilliamFeely/dxgl,WilliamFeely/dxgl