Pull request #1073: CAS-14738
Merge in CASA/casa6 from CAS-14738 to master
* commit '34e7f8d722235aea9f1e51000bda6e42287399d7':
indicate in the XML that use_durations is experimental, add final planned checks to checkActualAxes
move some shared code into separate functions to avoid code duplication.
propogate actualDurations warnings up to the the sdm tool for logging
moved some use_durations tests from the sdm tool test_task_importasdm
use_durations added at the top, test code added
values set in VMSData structure to be transferred to MS CAS-14738 : actual* fields are used where appropriate, still rough around the edges and not used out of the lower level, but worth committing finally.
