GWT: x.x, Admin, Save the last connection date in the user account

Currently, the last connection date is lost each time the portal restarts.

The first step is to save and update the last connection date in the user account.

The next step would be to set up a system of reminders for inactive accounts (to be specified)

(from redmine: issue id 656, created on 2014/03/06 by Alexey Lavrentev)

added priority::high type::task + 1 deleted label

changed milestone to %Portal 0.6

OK on Test portal (the last connection date persists)
A new ticket #664 (target Portal X.X) has been created for the reminders.

(from redmine: written on 2014/03/10 by Alexey Lavrentev)

OK BFM portal

(from redmine: written on 2014/03/14 by Alexey Lavrentev)

closed

assigned to @mdecorde