update required redis-py version range

fixes #1339
Coerce quotas to int
Correct test
Handle unsubmitted options
Optimize bulk deletion to use LIMIT
Correct call to update option
Redirect old team-based group URLs
Lower logging level of invalid cursor
Merge pull request #1340 from slafs/newer-redis-py

update required redis-py version range
Various fixes for wall

- Correct link media
- Correct get_stats endpoint
- Fix emptyMessage usage (defaults were overwritten)

Refs GH-1337
Return 404s for mismatched groups
List PL/SQL (fixes GH-1322)
Optimize out ScoreClause update
Upgrade Django to 1.6
Update ignore patterns to exclude vendor and migrations explicitly
Revert change to migrations path
Bump session cookie name for Django 1.6
Various additions to changelog
Remove use of atomic around EventManager.save
Dont wrap save_aggregate in atomic transaction