-LLCached[COA]Control can now be static const. Use for readonly access.

-const'd all readonly LLCached[COA]Controls to prevent altering by mistake.
-added get() accessor to LLCached[COA]Controls to return cached type explicitly without manual casts.
-added missing operators to LLCachedCOAControl
-Converted a few more settings to LLCached[COA]Control
-Fixed LLColor4U -> LLSD -> LLColor4 problems in LLCachedControl

Ascent functionality fixes:
-Tag coloring pulled out of getClientInfo(Redundant. idleUpdateNameTag already handled it)
--Tag and color substituted at render-time. Simple boolean logic. Neglible perf penalty.
-Fixed llinfos spam if AscentShowSelfTagColor = false
-Client tag updated less superfluously

indra/newview/lltoolmgr.cpp

@@ -239,7 +239,7 @@ bool LLToolMgr::inBuildMode()
 	// when entering mouselook inEdit() immediately returns true before 
 	// cameraMouselook() actually starts returning true.  Also, appearance edit
 	// sets build mode to true, so let's exclude that.
-	static LLCachedControl<bool> build_btn_state("BuildBtnState",false);
+	static const LLCachedControl<bool> build_btn_state("BuildBtnState",false);
 	bool b=(inEdit() 
 			&& build_btn_state
 			&& !gAgent.cameraMouselook()