Added a timeout to the zmq messages.
Implemented batches in which the event_builder collects data for a time, pauses and flushes the workers/writers, and resumes data taking after a dead time.
Merge branch 'mws-dev' of https://github.com/mwsmith2/slac-daq into mws-dev
merged in aaron-dev
Merge branch 'aaron-dev'
Event Builder now sends data in batches that can be checked have the same size, confirming synchronization, before writing.
Merge branch 'master' into mws-dev
merged aaron-dev
Merge branch 'master' of https://github.com/mwsmith2/slac-daq
pulling
Merge branch 'aaron-dev'
ZMQ context now destroyed shortly after message is sent.  Should fix hangs.
Fixed merge conflict in online/start_online.py.
added option for continual histogram refreshing