Fix help message for cleanup command

It was copied and pasted from upgrade
Merge pull request #1124 from DarkHorseComics/fix_cleanup_help

Fix help message for cleanup command
Remove blurb about bcrypt/secure
Remove invalid middleware
Remove static files magic from runserver
Kill IfModifiedSince in DEBUG
Note runserver command
Execute all is_rate_limited entrypoints
Correct version on flavor ua
Correct version on os
symlink static directory
Move serializers into API and minor refactor
Patch socket.getfqdn in tests
Merge branch 'master' into ember_static

Conflicts:
	src/sentry/management/commands/runserver.py
Various tweaks to Group model format
Use minified ember/ember-data for caching
use minified d3
use minified jquery
Endpoints and tests for group resolve, bookmark, markseen, and delete
Merge branch 'ember_static' of ssh://192.168.1.5/home/vagrant/sentry into ember_static