Changed local_settings.py option for sqlite3's database location.

This was causing the db file to be placed in /var/lib instead of /opt/graphite/storage/graphite.db so I changed it to the proper place. This caused the Exec['init-db'] to run on every puppet run. The effect of this change should stop that.
Changed config.pp Exec['init-db'] to use python's full path. This was causing puppet to fail to run
Merge pull request #8 from pranav/master

Put graphite.db in correct place and using python's full path.