Track glEnable states via static refs instead of map lookups.

Sync light state, bound shader, and various gl context states similarly to render matrices.
Texture handles now refcounted, as multiple viewer textures could ref the same handle (cubemaps do this)
Clean up gl extension loading a bit. Not necessary, but only look for ARB variants if not included in current core version. Removed unused extensions.
Use core shader api if supported, else use ARB. (FN signatures are identical. Just doing some pointer substitution to ARB if not core.)
Attempt at improving VBO update batching. Subdata updates better batched to gether per-frame.
There's probably other stuff I forgot that is in this changeset, too.

Todo: Fix lightstate assertion when toggling fullscreen with shaders off.

indra/newview/llwlparammanager.cpp

@@ -268,9 +268,7 @@ void LLWLParamManager::addAllSkies(const LLWLParamKey::EScope scope, const LLSD&
 {
 	for(LLSD::map_const_iterator iter = sky_presets.beginMap(); iter != sky_presets.endMap(); ++iter)
 	{
-		LLWLParamSet set;
-		set.setAll(iter->second);
-		mParamList[LLWLParamKey(iter->first, scope)] = set;
+		setParamSet(LLWLParamKey(iter->first, scope), iter->second);
 	}
 }
 
@@ -606,9 +604,9 @@ bool LLWLParamManager::hasParamSet(const LLWLParamKey& key)
 	return getParamSet(key, dummy);
 }
 
-bool LLWLParamManager::setParamSet(const std::string& name, LLWLParamSet& param)
+bool LLWLParamManager::setParamSet(const std::string& name, LLWLParamSet& param, LLEnvKey::EScope scope)
 {
-	const LLWLParamKey key(name, LLEnvKey::SCOPE_LOCAL);
+	const LLWLParamKey key(name, scope);
 	return setParamSet(key, param);
 }
 
@@ -621,9 +619,9 @@ bool LLWLParamManager::setParamSet(const LLWLParamKey& key, LLWLParamSet& param)
 	return true;
 }
 
-bool LLWLParamManager::setParamSet(const std::string& name, const LLSD & param)
+bool LLWLParamManager::setParamSet(const std::string& name, const LLSD & param, LLEnvKey::EScope scope)
 {
-	const LLWLParamKey key(name, LLEnvKey::SCOPE_LOCAL);
+	const LLWLParamKey key(name, scope);
 	return setParamSet(key, param);
 }