Rename Django project to zproject.

This includes a hack to preserve humbug/backends.py as a symlink, so
that we don't need to regenerate all our old sessions.

(imported from commit b7918988b31c71ec01bbdc270db7017d4069221d)

zerver/lib/queue.py

@@ -18,7 +18,7 @@ from zerver.lib.utils import statsd
 # out from bots without having to import pika code all over our codebase.
 class SimpleQueueClient(object):
     def __init__(self):
-        self.log = logging.getLogger('humbug.queue')
+        self.log = logging.getLogger('zulip.queue')
         self.queues = set()
         self.channel = None
         self.consumers = defaultdict(set)