Implement other backends for tlog and queues

[scaleupcto]

Using Mongo for the tlog and queues is a PITA. The problem is Mongo never recovers filesize, the transaction log is continually growing and shrinking. Eventually it fills the disk even though the document count in the queue is low, and one prunes their tlog...

Instead, implement Doctrine for the tlog (you can choose your backend in config then, like postgres) and implement resque workers for queue (backed by redis)

[scaleupcto]

Working on doctrine here: #6

[scaleupcto]

We're working on the resque workers here, here and here.