Only one page

We'll use a single page for the demands list.
Display code & name change

Some display code for DemandsView and PersonalView, and name change: in
Offer, Demands & Users are directly referenced (the objects), instead of
their identifier.
Name change in Demand

In Demand, the demanding user is now directly referenced as an object
(_user), instead of his identifier (_userId).
Minor fix to fit previous commit

Access to a deleted object now impossible...
Login stub

LoginWidget main functions, without the POST/Ajax code.
Various updates

Get the values in the RegisterView button callback;
Fix the HTML to fit the js;
Add a global "x|->hashFunction( x )" in App.js
Very basic StringChecker
Almost working interface

Still a stub linked version - no POST/ajax calls, but everything seems
to be working.
Same as previous

Fixes to App.js for the almost working version.