New Post Creation Template changes

Removes old new post creation template and unifies both inline and main application post creation. Includes UI for Question/Discussion post types, help text strings, and a general styling cleanup of this UI. 
Commits will be squashed down after review is complete. 

@gwprice @jimabramson - This still start out the feature branch we can add in all work for the new question type on. 
@frrrances - could you take a look through the FED work here. A lot was moved around, but feel free to comment on anything and I'll work towards cleanup (or specifically listing out follow-up FED cleanup for styling I didn't actually edit in a separate story. Thanks! 

Old: https://www.dropbox.com/s/6l7np6r2izl5trk/Screenshot%202014-07-09%2013.55.54.png
New: https://www.dropbox.com/s/xzke3uqh6mabebz/Screenshot%202014-07-09%2014.58.15.png
New: 

we lost an aria-described-by tag here, is that ok?