Move thread tag/post icon picker out to own folder.
Parse secondary thread tags like "Ask" or "Tell" from new thread form.
Show secondary thread tags in icon picker.
Extract a thread tag view.
Use thread tag object for PM parsing/composing.
Use thread tag object for new thread parsing/composing.
Centralize empty thread tag image names.
Use a thread tag button that can show secondary tags.
Handle secondary tag selection in thread compose view.
List secondary post icons when asked.
Include secondary post icon when posting threads.