Remove unused Message utility class
Use new-style classes everywhere
Don't take unnecessary kwargs in exposed methods
Set title to 'FreedomBox' instead of 'FreedomBox Dashboard'
Add Django urlpattern files for each module

This is in anticipation of the routing changes to come. The changes themselves do nothing.
Add a menu method to find menu items by URL
Fix minor grammatic error in firewall status page
Add Django custom error handling pages for 404 and 500 errors
Use Django dispatcher instead of CherryPy dispatcher

This commit is big because anything small breaks the code.

- Django dispatcher is based on regular expressions and does not need a tree structure
- Reduces a lot of unnecessary dependencies among modules
- Use Django sessions middlewear instead of CherryPy sessions
- Introduce dependency based modules instead of numeric load order
- Remove PagePlugin and simply use Django views
- Eliminate page rendering wrappers in favor of Django context processors
- Use custom auth for now until replaced by Django auth middlewear
- Use Django templated 404 and 500 error pages
Remove unused PagePlugin
Remove unused template rendering wrapper
Merge pull request #82 from SunilMohanAdapa/django-routing

Use Django dispatcher instead of CherryPy dispatcher