New feature: auto-register Plone users on login

- New feature implemented, so Plone users might be registered
  in automatic into the jabber server on login. Upgrade
  step was also added to update the new added property to
  existing installations.
  [alecghica]
Removed auto_registered property from registry and fixed deregister all users

- Removed auto_register property from registry and the upgrade
  step related to this

- Fixed "Deregister ALL Users" function, as credentials were
  left un-deleted under IXMPPPasswordStorage resulting in
  various errors when register/deregister users
Removed comments left behind
No need to refresh browser for users registered on login

- Bug fix: no need to refresh browser for users registered
  on login, they are binded on the fly
  [alecghica]
Now @@xmpp-loader return bind_retry, no more from handlers.js
Fixed error when de-register users with empty string as username
Merge remote-tracking branch 'onlogin/master'

Conflicts:
	docs/HISTORY.txt
Cosmetics
Fixed auto-subscribe

- Bug fix: fixed subscribing when a new plone user is added
  [alecghica]
- Bug fix: fixed that users were only being auto-subscribed to
  other users added in that current session
  [alecghica]
- Bug fix: new users are now auto-subscribed only
  to existing XMPP users
  [alecghica]
- Change: code cosmetics
  [alecghica]
Merge pull request #10 from alecghica/master

New feature: auto-register Plone users on login.

Great job, thanks!