edx/edx-platform — pull request #5276 by polesye (2014-09-18 08:17:36+00:00)
Title: Change the topic of a previously posted post.

Ticket: [TNL-171](https://openedx.atlassian.net/browse/TNL-171)

**Acceptance criteria:**
Share the Topic Area dropdown from the New Post view to the Edit view of a post.
We'll follow this on with a small UX cleanup if there's any UX work needed (no pre-work from the UX team).