Merge pull request #997 in CASA/casa from hf-drs17 to master
* commit '848c601283d043a1695d41aee8ba7d5d2e93faf6':
resolve interesting race condition with lambdas used across threads (casa6/casaviewer)
Merge pull request #996 in CASA/casa from hf-drs16 to master
* commit '90c47cdbeb42f2f306bc1d94aebc4e7a250731b0':
changes for python module for casaviewer (casa6)