Fixed API baseline tags
Add missing override annotation for 1.6.  Began support of static null analysis support.
Merge remote branch 'origin/develop-1_8' into develop-1.9

* origin/develop-1_8:
  Fixed API baseline tags
Add problem filter for addition of version constraint. Update API tags for 1.9.1
refs #1292 remove duplicate array copy in process() for 16-bit data
packet. also corrected warning msg to refer to 16-bit in this case vs
4-bit.
Merge branch 'develop-1_8' into develop-1.9
Updating version number to match manifest in hopes of fixing build
Adding null annotations to resolve workspace errors
Updating version number to match manifest
ref #1255 - clarified port names in Port Monitor and Audio Port Playback views
edited variable names
refs #969 Added warning if a .prf file is added to a service without the
PropertySet interface
Apply domain persistence mods
user-specific prefs implementation. domain regsitry object still shared among all users.
Latest domain and prefs persistence mods
Completed user-specific prefs persistence
add new rap and rcp plugins to pom.xml and feature.xml files
Fix ClastCastException
remove unused improts
Use session singleton for domain manager registry container, or singleton shared across sessions when shared domains proeprty is set