Pull request #960: CAS-14462
Merge in CASA/casa6 from CAS-14462 to master
* commit 'e827380fe11235151364944a8893ad9bb152d61c':
A minor modification to the docstring
Add Q, U, V images to the weblog
A minor bug fixes in almastkutils functions
Change data path from a local one to one's in data repo and add missing iter1 tclean arguments.
Add a description for the polarized calibrator imaging test
Fix image_stats not to include metrics not requested
Turn on metric comparison using local expdicts json file
Add few missing metrics and minor fixes
Update fit_regions for Test 15 based on the CAS-14462 comment Add missing metric keys
Initial version of test_cal_mfs_IQUV
