Anonymous login

[GoogleCodeExporter]

Brief description of the enhancement:
It should be possible to permit an anonymous login to jardin

Detailed use-case:
If enabled by configuration, anonymous login should be the default option. 
An user enters to jardin clicking on login button without providing any 
credential.
On the other hand, if a user wants to be authenticated in order to acquire 
provided privileges - and the system is configured to do that -, switches to 
authentication mode on login window, provides credentials and logins.

Original issue reported on code.google.com by gpantane...@gmail.com on 3 Nov 2009 at 2:11