Ensure blocking operations are performed in threads

[Kit Barnes]

Pretty sure the only blocking operation we do at the moment is chatter over a port and tornado should handle that automatically for us (as we're using their library to do it). Nevertheless we should check this and make sure that we maintain this property when we e.g. add SQLAlchemy.

[hamhut1066 NA]

Another blocking point is writes to the database, we could structure it to be out of band. giving us nice quick response times, pushing future writes to the database through a message queue.