Innitial commit of experimental v2 texture system port work. Compiles and runs on windows, at least. Fixing bugs as they come.

Need to test:
localassetbrowser
preview related floaters
hgfloatertexteditor
maps
media textures! Currently very hacky
web browser
alpha masks on avatars
bumpmaps
Are all sky components appearing?
LLViewerDynamicTexture (texture baking, browser, animated textures, anim previews, etc)
Snapshot related features
Customize avatar
vfs floater
UI textures in general
Texture priority issues

indra/llmath/llvolume.h

@@ -909,7 +909,8 @@ public:
 									std::vector<S32> &segments, 
 									const LLVector3& view_vec,
 									const LLMatrix4& mat,
-									const LLMatrix3& norm_mat);
+									const LLMatrix3& norm_mat,
+									S32 face_index);
 
 	//get the face index of the face that intersects with the given line segment at the point 
 	//closest to start.  Moves end to the point of intersection.  Returns -1 if no intersection.