Reorganize Directory structure.

The app, env, and static directories now live side by side on the
guest machine within the /usr/local/otm folder. We previously had
problems with littering the /usr/local folder with multiple
directories that were part of this project.

Fixed vagrant shell provisioner to check if the share directory is
mounted before trying to unmount it.

Cleaned up and added comments to the fabric file.
Update django requirement to 1.5
Add fixture for admin superuser and test instance.

There is an instance called ExampleTreeMap and an initial superuser
with username vagrant and password vagrant.
Update templates to receive instance from the request.

Added additional context processor to expose the request to the templates.
In order to do this, we had to paste in the original context processors
that Django uses by default.

Changed views to stop passing in instance as a top-level object.

Updated templates to access request.instance instead of instance.
Wrapping base script tags in a template block.