Pull request #568: CAS-13672
Merge in CASA/casa6 from CAS-13672 to master
* commit 'ed29f279a590f17037a91b71744649064bd13a00':
add available options of maskmode in the shortdescription
fix a simple mistake for parameter number: three -> four
deleted checking for maskmode='interact'
update sdbaseline inline help for the maskmode parameter