initial django 1.4 support
Merge branch 'master' into django1.4

Conflicts:
	askbot/feed.py
Merge branch 'master' into django1.4
threads can be now deleted and restored
Merge branch 'master' into group-messaging
responses to archived messages kick them back to the inbox
re-enable the messages panel once again
display of deleted and new threads seems to work correctly
most recently edited threads are on top
added test cases for bolding of headline for new updates and for updating the headline text on responses
send email alert when PMs are sent
Merge branch 'master' into group-messaging
added sent mailbox, message counts in threads, fixed some bugs and added test cases
Merge branch 'haystack'
Merge branch 'master' into group-messaging
added messages count to inbox
Merge branch 'master' into django1.4
added url to the personal message notification, sidebar message counter to the inbox, updated test case for the PM email alert
fixed feed url issue and template context middleware issue more info here: http://stackoverflow.com/questions/7470179/module-django-core-context-processors-does-not-define-a-auth-callable-reques
added fix for Message model