incorporate mscweb
Improved DA disconnect logic slightly.  Now we are stopping the DA
server as soon as we are notified to do so.
Changes to support the last link in the serial conection chain
extended deployment service impl
Adjust platform driver to always publish same set of fields, with different emptinesses.
Adjsut platform granule unit test for new format.
Adds additional support for derived data products
Adds invisibility attr and VEL3D test data
Updates submodule
Merge pull request #1239 from lukecampbell/dp-work

More work on Derived Data Products
Merge pull request #1237 from unwin/d88d9bdd0778812e7335780d3f419c254aa6b117

Serial port_agent_process mode last mile of code.
Merge pull request #1234 from wfrench/master

Improved direct access disconnect logic
Merge pull request #1238 from ooici/jira1027_impl

extended deployment service impl
Changed UNS.get_subscriptions to use RR instead of discovery
Merge pull request #1240 from mmeisinger/master

Changed UNS.get_subscriptions to use RR instead of discovery
Added UNS support for batch notifications in case no ElasticSearch
Bump EPU
Release Version 2.0.51
Bump Version to 2.0.52-dev
Exchange bootstrap reenabled