SW-657: Backported fixes from 4.0 into trunk

CEP/Pipeline/framework/lofarpipe/monitoring/poller.py

CEP/Pipeline/framework/lofarpipe/support/group_data.py

CEP/Pipeline/framework/lofarpipe/support/remotecommand.py

CEP/Pipeline/framework/lofarpipe/support/subprocessgroup.py

CEP/Pipeline/framework/lofarpipe/support/usagestats.py

CEP/Pipeline/recipes/examples/master/example.py

CEP/Pipeline/recipes/sip/master/new_bbs.py

CEP/Pipeline/recipes/sip/master/setupparmdb.py

CEP/Pipeline/recipes/sip/master/vdsmaker.py

CEP/Pipeline/recipes/sip/nodes/copier.py

CEP/Pipeline/recipes/sip/nodes/imager_create_dbs.py

CEP/Pipeline/recipes/sip/nodes/imager_finalize.py

CEP/Pipeline/recipes/sip/nodes/imager_prepare.py

CEP/Pipeline/recipes/sip/nodes/long_baseline.py

CEP/Pipeline/recipes/sip/nodes/selfcal_finalize.py

CMake/FindPythonModule.cmake

LCS/MessageBus/src/messagebus.py

LCS/MessageDaemons/src/CMakeLists.txt

LCS/MessageDaemons/webmonitor/QPIDWebserverJSON

LCS/MessageDaemons/webmonitor/start_QPIDWebMonitor