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/newview/llstartup.h

@@ -33,7 +33,7 @@
 #ifndef LL_LLSTARTUP_H
 #define LL_LLSTARTUP_H
 
-#include "llimagegl.h"
+class LLViewerTexture;
 
 // functions
 bool idle_startup();
@@ -76,7 +76,7 @@ typedef enum {
 
 // exported symbols
 extern bool gAgentMovementCompleted;
-extern LLPointer<LLImageGL> gStartImageGL;
+extern LLPointer<LLViewerTexture> gStartTexture;
 extern std::string gInitialOutfit;
 extern std::string gInitialOutfitGender;	// "male" or "female"