Merge pull request #97 in CASA/casa6 from CAS-12900 to master
* commit '3ae4ce373aee66090e9d7e0b31256c11d2524b89':
Changed the way calpath was found so it shouldn't only look in casatasks
remove genmake rsync_data target (CAS-12900)
make casadata pkg optional for build/testing (CAS-12900)
switch to using distro data repository from casadata pkg (CAS-12900)