Merge pull request #13 in CASA/casaviewer from CAS-13145 to master
* commit '11542d843b55a60c6c3e0b64b2a0367fa345ef4c':
rundata( ) moves to casatools.ctsys (CAS-13145)
casadata is no longer required (CAS-13145)
switch to casatools for runtime data location (CAS-13145)