Add Create/List/Update views for expense model

The views use the following URLs dispatcher:
 * /expense/new : CREATE
 * /expense/ : LIST
 * /expense/<id> : DETAIL
 * /expense/<id>/update : UPDATE
and are based on generic class-based-views (CBV).

The base.html template is generated by HTML5 boilerplate.
Signed-off-by: Balthazar Rouberol <balthazar.rouberol@mapado.com>
Static files of HTML5 boilerplate

Signed-off-by: Balthazar Rouberol <balthazar.rouberol@mapado.com>
New app: roommate

The roommate app will manage the colocation roommates actions and views.

Warning: a differentiation must be made between a roommate and a user.
A user is simply used for login, authentication, acl, etc. The roommate
is the "buisness" user model, holding all the expenses, etc.

There is a OneToOne relationship bewteen the Roommate and the User,
and each time a User is created, a Roommate is autmagically created,
using the User.post_save signal.

The Roommate forms have been tweaked (using ModelForms) so that they
use the User forms.
Signed-off-by: Balthazar Rouberol <balthazar.rouberol@mapado.com>
Visual tweaks

Signed-off-by: Balthazar Rouberol <brouberol@imap.cc>
Expense detail template

Signed-off-by: Balthazar Rouberol - brouberol@imap.cc