Isolate default store params in its module
Load backend from environment variable if present
Check length of time format for ':' conditional in attime.py

This fixes https://github.com/graphite-project/graphite-web/issues/511 and allows you to use time format like '00:00' again.
remove sys.path hack, manage.py one level up
Remove old-style admin classes
Add cyanite store backend
fixed conflict