[fix #136] Handle correctly role cache

Remove correctly the cache of role when user edit it.

Check parameters before handling.
[fix #135] Manage Firefox password manager

Passwords saved in the Firefox password manager are now correctly filled
in the login form
[fix #138] Change the label of the submit button in paper option page

Change the label of the submit button from 'edit' to 'save'
Improve author and reviewer selection

The enter key is now used to select a user instead of submitting the
form.
Improve translation