Added scheduled job for timing out leveling operation.  Lots of stuff
having to do with chunker and use of chunker; added coarse chunker.
Added method to start separate thread for calling on_event()--which
can get blocked--from listener thread. Also using chunker in a hierarchical
way.
Added unit test for async_send_event.
Incremental.
Added resume leveling for case where instrument is in leveling upon driver
initialization.
Incremental.
Tests passing (qual tests have a problem with IMS...not sure what is going on).
Adding nano sensor to BOTPT.
Unit and Integration tests working.
Firehose test passing.
All unit tests working again.
Added set_time command and associated tests.
Merge remote-tracking branch 'upstream/master'
Fixed problem with new packet reception scheme where we were susceptible to
negative count exceptions.
Merge pull request #118 from deverett/master

Fix Port Agent Client Negative Count Exception
added unit test for dataset drivers
unit tests complete
progress on CTDPF qualification tests