Merge pull request #309 in CASA/casa6 from CAS-8755 to master
* commit 'd1095cfc530eda104fde17715969559c2adac281':
fix a delete temporary file issue
has_key has disappeared in python3
fix a conversion of rownr_t to uInt that compiled in casa5 but not casa6
cleanup of temp files when automask is used
merge changes due to CAS-9386 to make it work here
tweaked FDSize check error message to be more informative
add check of expected maximum FDSize to test_perf_tclean_mem_setweighting.py
removed a couple of print statements
fixed a multi ms multi field bug
making use of imagingweight scratch column for perchanweight now..
