refetchResources refreshes the view

When resources are refetched, all viewInstances are removed and current
one will be recreated. This way resources can be reloaded without need
to refresh the whole page.

Example:

$('#button_id_which_refreshes_resources').fullCalendar('refetchResources');

src/Calendar.js

@@ -332,6 +332,22 @@ function Calendar(element, options, eventSources, resourceSources) {
 
 	function refetchResources() {
 		fetchResources(false);
+
+		// we have to destroy all view instances and recreate current one
+		viewInstances = [];
+
+		// remove current view from display
+		currentView.element.remove();
+
+		// create current view again
+		currentView = viewInstances[currentView.name] = new fcViews[currentView.name](
+					newViewElement = absoluteViewElement =
+						$("<div class='fc-view fc-view-" + currentView.name + "' style='position:absolute'/>")
+							.appendTo(content),
+					t // the calendar object
+				);
+		// let's render the new view		
+		renderView();
 	}
 
 	// called when event data arrives