Created new catcher class DemultiplexCatcher. This returns a list of dictionaries, each containing the data and clock for a separate channel. Added create_data_products_dict to aggregator to take into account the dictionaries rather than named tuples. May switch back to named tuples, but the output will stay demultiplexed.

Added the code running on the roach to the branch under new directory ppc. This code sends data from the filebuffers in the roach as UDP packets. Also included the python program startup_fileserver that runs this on the roach without having to manually ssh into the roach.