Fix for autosave

Re-introduces the “tw-auto-save-wiki” message. The previous approach of
automatically triggering autosave whenever a tiddler changed meant that
changing configuration changes in control panel was triggering an
autosave. Using the explicit message gives us better control of the
situations in which we’ll autosave.

Now we solve the earlier problem of there being outstanding tiddler
change events at the time that we process the “tw-auto-save-wiki” by
deferring the autosave until the outstanding change event comes in.

core/modules/utils/pluginmaker.js

@@ -71,6 +71,8 @@ exports.repackPlugin = function(title,additionalTiddlers,excludeTiddlers) {
 			$tw.wiki.deleteTiddler(title);
 		}
 	});
+	// Trigger an autosave
+	$tw.rootWidget.dispatchEvent({type: "tw-auto-save-wiki"});
 	// Return a heartwarming confirmation
 	return "Plugin " + title + " successfully saved";
 }