* Some strings were not detected by makemessages (for example in javascript files, behind comments...). There are still some issues with that but I think I'll have to wait a future Django release.
* Support for per-user language selection is almost done.
see #166
Many updates in this commit:
* first work on the webmail plugin, for now only emails listing and folders browsing is supported...
* New login form,
* New graphical layout (still needing improvments)
* code factoring between webmail and quarantine plugins
* etc.