made test_settings import from settings_changeme and override where necessary. updated some packages
removed accidental package inclusion
added migration to remove old djkombu tables for update of kombu package

all data is deleted, however, the task data should be transient, so nothing should be lost
delete tables only if they exist

used code from https://bitbucket.org/andrewgodwin/south/pull-request/24/fix-for-430-with-tests-and-related-cleanup/diff
reason: we want to avoid fake for auto-updates via chef/salt
Merge pull request #252 from grischa/master

settings and package update