Fixed a couple rare null pointers

astrid/plugin-src/com/todoroo/astrid/actfm/TagViewFragment.java

@@ -255,6 +255,7 @@ public class TagViewFragment extends TaskListFragment {
             }
 
             TaskListActivity tla = (TaskListActivity) getActivity();
+            if (tla != null)
                 tla.setCommentsCount(unreadCount);
         }
     }

astrid/src/com/todoroo/astrid/activity/TaskListFragment.java

@@ -714,6 +714,7 @@ public class TaskListFragment extends ListFragment implements OnScrollListener,
      * broadcast. Subclasses should override this.
      */
     protected void refresh() {
+        if (taskAdapter != null)
             taskAdapter.flushCaches();
         loadTaskListContent(true);
         taskService.cleanup();