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.
this feature).
Back to previous 'locale' location because it's not possible to access
translations that are defined inside the 'templates' directory while scanning
with django-admin.py from the 'admin' directory.
Antoine Nguyen