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/llviewerinventory.cpp

@@ -811,8 +811,13 @@ bool LLViewerInventoryCategory::exportFileLocal(LLFILE* fp) const
 
 bool LLViewerInventoryCategory::acceptItem(LLInventoryItem* inv_item)
 {
-	bool accept = true;
+	if (!inv_item)
+	{
+		return false;
+	}
+
 	// Only stock folders have limitation on which item they will accept
+	bool accept = true;
 	if (getPreferredType() == LLFolderType::FT_MARKETPLACE_STOCK)
 	{
 		// If the item is copyable (i.e. non stock) do not accept the drop in a stock folder