Pull request #660: CAS-13904
Merge in CASA/casa6 from CAS-13904 to master
* commit '243c33d254d18c279100b8e8c9c9b5ef6f2426e9':
Fix model image paths
Add print statements to debug the test failures
New tests for the updated VLA model images
Add new tests for new VLA models at K, X, and C-bands
A new test for the new 3C48 model image