Quick cleanups.
Handle post status reporting with task status page.

Since we don't know when will the post succeed, a new page is added
for querying post status every 1 second. If the post is succeed,
user will be redirected to the appropriate path automatically.
Use BaseTaskView instead of dedicated TaskView.

Since we need to render different template for each task status, using
another request dispatcher to handle task and reuse the post URL makes
more sense in a long run.
Handles periodic checking for task status in JavaScript component.
Fix posts bumping no longer working.