Giant VMM merge, still need to compile it and fix llfloatermarketplacelistings

Merge VMM up to change 187902d9c4afd2990acddeb964c928179a52d189

mAllowWear=>mAllowOpen (should probably just remove this altogether though
inventory_panels now accept the "show_root_folder", "allow_drop_on_root", "allow_open", and "use_marketplace_folders" attributes.

Other stuff in this commit:
LLPanelInjector~
Sync lltooldraganddrop to alchemy
Sync notifications up with alchemy
Reorganize notifications some, to better merge with upstream
Remove duplicate InventorySortOrder in settings map
There's a bit of a weird folderview merge mixed into here, I wouldn't trust it, but this thing is so god damn tangled I can't go back now~

Wouldn't have been possible without help from Shyotl and music by Amanda Palmer

indra/newview/llagent.cpp

@@ -4107,6 +4107,12 @@ void LLAgent::handleTeleportFinished()
 		LLNotificationsUtil::add("PreferredMaturityChanged", args);
 		mIsMaturityRatingChangingDuringTeleport = false;
 	}
+
+	// Init SLM Marketplace connection so we know which UI should be used for the user as a merchant
+	// Note: Eventually, all merchant will be migrated to the new SLM system and there will be no reason to show the old UI at all.
+	// Note: Some regions will not support the SLM cap for a while so we need to do that check for each teleport.
+	// *TODO : Suppress that line from here once the whole grid migrated to SLM and move it to idle_startup() (llstartup.cpp)
+	check_merchant_status();
 }
 
 void LLAgent::handleTeleportFailed()