Update basket only when functional area memberships change.
[fix bug 908053] Fix group member counts in admin.
Add GroupManager that provides member_count.

* Also add total_member_count, full_member_count and
  pending_member_count in Admin Panel.
Beautify GroupAdmin.
[fix bug 980887] Speedup group browsing.
[fix bug 948530] Link to larger versions of profile pictures.
[fix bug 1000938] Proper filtering for group memberships.
Tests cleanup.
[fix bug 1001339] Fields date_joined and date_last_login are not required.
[fix bug 1001342] On UserProfile delete, delete also the related User object.
Fix deprecation warnings.

* DeprecationWarning: django.conf.urls.defaults is deprecated; use django.conf.urls instead
Merge pull request #924 from glogiotatidis/948530

[fix bug 948530] Link to larger versions of profile pictures.
Merge pull request #928 from glogiotatidis/1001342

[fix bug 1001342] On UserProfile delete, delete also the related User obj.
[fix bug 848565] Make email address a unique field.
[fix bug 1001425] Make login button float on the right side.
Enable timezone support.
Merge pull request #931 from glogiotatidis/fixcelerytimezone

Enable timezone support.
Merge pull request #927 from glogiotatidis/848565

[fix bug 848565] Make email address a unique field.
Merge pull request #929 from glogiotatidis/dep

Fix deprecation warnings.
Merge pull request #930 from glogiotatidis/fixloginbutton

[fix bug 1001425] Make login button float on the right side.