cleanup section footer

There are a few minor glitches with the #section_footer area.  The biggest is a missing ID output for hidden sections.  This pull request is a general cleanup.
before:
![screen shot 2014-04-09 at 8 59 44 am](https://cloud.githubusercontent.com/assets/743499/2651484/e350e734-bf8d-11e3-915e-1a2f8cda2b88.png)

after:
![screen shot 2014-04-09 at 10 18 48 am](https://cloud.githubusercontent.com/assets/743499/2651487/e8ff4cd4-bf8d-11e3-9275-00ed9653d8b2.png)