Merge in CASA/casa6 from CAS-14272 to master
* commit '3ef88ee1bb5876d427e9a17c769178b8a34a5dc5':
Re-worded the location of JPL-Horzions table in the task's docstring. Removed casa5-related code. Updated the docstring for MIME format test to reflect the current behavior. Removed the old casadoc URL in the task xml.
removed debug print statement
Removed reference to ephemeris data in a MIME format file
One more bug fix to fix the test failures
Fix some bugs
Disable MIME format JPL-Horizons data support and delete JPLEphem_reader2