Enable stage length input

# What's changed

* Added form input for stage length. 
* Added the accordion group to put the timeline in.

![screenshot 2014-12-31 11 30 41](https://cloud.githubusercontent.com/assets/485583/5585481/79ace93e-90e0-11e4-93df-d7b5e834c943.png)

# What's next
* I think @emily-plummer wanted to look at stage length styling. This should now be possible!
'calcStageLength' is not defined.