Add BC6 support to nvtt lib and utils.

- Use 3x3 eigensolver for initial fit in ZOH.  Slightly better perf and RMSE than power method.
- Remove use of double precision in ZOH - speeds up by 12%.
- Fixed RGBM encoding that was broken for HDR images.
- Use gamma-2.0 space for RGBM for HDR images (improves precision in darks).
- Use UNORM instead of TYPELESS formats when saving a DX10 .dds file.  The TYPELESS formats break most viewers.
- Cleaned up warnings in ZOH code.
- Command-line utils will warn if you give them an unrecognized parameter.
- Added VS2010 profiling results.

project/vc9/Nvidia.TextureTools/TextureTools.cs

@@ -31,7 +31,15 @@ namespace Nvidia.TextureTools
 		BC3n = DXT5n,
 		BC4,
 		BC5,
-	}
+
+        DXT1n,   // Not supported on CPU yet.
+        CTX1,    // Not supported on CPU yet.
+
+        BC6,
+        BC7,     // Not supported yet.
+
+        DXT1_Luma,
+    }
 	#endregion
 
 	#region public enum Quality