Task type serialization change: module.name -> module:name

This is similar to the naming scheme used by entry points, and allows
clearer distinction between the module and name parts.
Added (experimental) kombu-based queue manager
Now generating task_id only if not specified by the user
Better to/from dict conversion of tasks (+ bugfix)
not self.conf.get(queue) -> self.conf.get(queue) is None
BaseQueueManager objects are now configurable, as other objects
Added kombu-based queue manager. Tests all green using memory:// transport
support for running tests on the kombu-based queue!
Disabled pep8 tests on (generated) Python3 code (dammit 2to3!)