Add binding_of_caller back
Add category_uid to categories for name hash
Modify root route
Modify migration to produce SHA/'s for existing users categories
Add method to set MD5 hash for categories
Find categories by uid
Routes using category_uid
Route using category_uid
Modify nav
Change username path to route to categories controller
Merge branch 'master' of github.com:jtg028/dunzo-signup into jack/remove-view-all
Remove slugs from categories