-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/lltoolfocus.cpp

@@ -216,7 +216,7 @@ void LLToolCamera::pickCallback(const LLPickInfo& pick_info)
 			gAgent.setFocusGlobal(pick_info);
 		}
 
-		static LLCachedControl<bool> freeze_time("FreezeTime",0);
+		static const LLCachedControl<bool> freeze_time("FreezeTime",0);
 		if (!(pick_info.mKeyMask & MASK_ALT) &&
 			gAgent.cameraThirdPerson() &&
 			gViewerWindow->getLeftMouseDown() &&