Pull request #785: CAS-14300
Merge in CASA/casa6 from CAS-14300 to release/6.6.1
* commit 'bc55fd5255b5fab402566548cad087189331d017':
For CAS-13544, remove CRs in xml text that seem to mess up formatting in casadocs.
For CAS-13544, updated test_task_polfromgain.py to use proper symbolic link to input data in casatestdata (checked in by scastro this date); cleaned up polfromgain.xml to match corresponding changes in casadocs.
For CAS-13544, further refinements to polfromgain task; complete revision of test_task_polfromgain.py
For CAS-13544: improved handling of parang cycles in discerning available parang range; temporarily disabled some unit tests pending updates
For CAS-13544, in polfromgain task, trapped insufficient parallactic angle coverage (via new minpacov parameter) to avoid implausible results, including a negative gain ratio that causes a 'math domain error' and failure of the task to complete.
