Pull request #1076: CAS-14867
Merge in CASA/casa6 from CAS-14867 to master
* commit '52fd7a98556ee8739148e2007a8a04ed5907d691':
Changed the name of the reference pccor cal table to avoid conflicts with master and 6.7.6 branches
Added a mechanism to unwrap phases for tones, which shall solve the issue of non referenced delays flipping signs.