Server side logic for directories.
Add support for index.ipynb
Add directory browsing to the dashboard.
Update styling of dashboard.
Adding proper breadcrumb support.
Tighten up vertical spacing of notebook list.
Adding btn-danger to Shutdown button.
Taking it down to 3px.
Tighten spacing of dashboard.
Cleaning up the dashboard CSS and fixing small visual problems.
Get the existing tests working.
Adding dashboard navigation tests for dir browsing.
Fixing casperjs tests to run on casperjs 1.0.x.
Nice dashboard page titles like /.../examples/notebooks/
Another variation of the dashboard page title.
Cleaning up JS tests controller.
FF Fix: missing scrollbars on inner_cells
fab css
Addressing review comments.

* list_dirs and get_dir_model added to base NBM class.
* Calling of list_dirs moved to handler.
* type=notebook added to notebook model.
don't strip '.ipynb' from notebook names in nblist

The only place the extension is not wanted is editing a name during upload.
Everywhere else, it's actually wanted.