Don't display quota if unlimited.

fix #566
Check if dates are too old only when the reply is activated.

fix #570
Define the foreign key on mailbox's side.

fix #543
Update the quota record when a mailbox is renamed.

see #543
Specific virtualenv instructions added.

fix #563
External links added.

fix #565
Amavis configuration instructions added.

fix #567
mod_wsgi daemon mode instructions added.

fix #568
Make sure notifications are always visible.

fix #549
Convert signature to unicode.

fix #582
A brief note about media permissions.

fix #569
ValueError can be raised by the datetime module too...

fix #556
Version 1.1.5
Handle empty subjects properly.

fix #586
Regroup all queries in one place.

see #589
Fixing demo fixtures.
Do not override the default history object.

fix #588
Few fixes in the postgres backend.

see #589
Adding some comments.

see #589
Merge branch '1.1.x' into refactoring/amavis_queries