-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/llstatgraph.cpp

@@ -109,7 +109,7 @@ void LLStatGraph::draw()
 	//				gColors.getColor("ColorDropShadow"), 
 	//				(S32) gSavedSettings.getF32("DropShadowFloater") );
 
-	static LLCachedControl<LLColor4> menu_default_color("MenuDefaultBgColor",LLColor4(0,0,255),gColors);
+	static const LLCachedControl<LLColor4> menu_default_color("MenuDefaultBgColor",LLColor4(0.f,0.f,0.f,1.f),gColors);
 	color = menu_default_color;
 	gGL.color4fv(color.mV);
 	gl_rect_2d(0, getRect().getHeight(), getRect().getWidth(), 0, TRUE);