Edit population titles

Replacing earlier PR #395 

## Story
* https://www.pivotaltracker.com/story/show/75134126

## Notes
Took the inline editing example from the edit user functionality in the admin page, seems to work pretty well here.

## Screenshot
![screenshot 2014-09-17 09 41 16](https://cloud.githubusercontent.com/assets/2136286/4304401/6740bc02-3e70-11e4-8974-cf1caf31a093.png)