added 0MQ interface to workflow service

cdb_dm_integration_notes.txt

+- DS service
+  - runs on extrepid
+- DAQ service
+  - APSU station, runs on ctlsdaqsrv2
+- Catalog service
+  - APSU station, runs on ctlsdaqsrv2
+- Processing (Workflow) service
+  - can run workflows for each file, or for set of files, in real-time
+  - RT workflow args can be set via PV
+  - DAQ needs to send burst number (e.g, file 3/10)
+  - can always request workflow processing on a set of files (post processing)
+  - need portal that will be able to submit processing job
+  - need to be able to keep track of processing jobs and their results
+
+- DM/CDB integration plugin
+  - triggered via CDB:<qrId> keyword
+  - adds DM-document property, will have metadata catalog URL, 
+    file download URL, metadata key/value pairs as needed
+  - must be able to associate multiple qrID's
+- CDB Document domain
+- CDB/DM integration plugin: needs to be able to click on the file to see the 
+  metadata, or to download the file
+- DM/SDDS plugin
+  - triggered by ".sdds"
+  - reads parameters, converts them to metadata
+
+- Use Case: StudiesSession-20170422
+  - From CDB perspective StudiesSession-20170422 is an item in the 
+    Documents Domain
+  - From DM perspective, StudiesSession-20170422 is an experiment on an APSU 
+    station
+  - When collecting DAQ data, DM will automatically asign all files to be
+    part of the StudiesSession-20170422 experiment
+  - DM/CDB plugin will add DataFile property to StudiesSession-20170422 for 
+    each file
+  - CDB/DM file property handler will be able to display DM metadata (URL link)
+    and download file; later, it may be be able to submit processing job
+    to DM processing service