Task #9599: Changed scheduler to not set input files for CEP4 and ignore pipelines managed by SLURM with a start time in the past.

Task #9192: Use C++11, Ubuntu 16.04, OpenBLAS, AOFlagger 2.8.0, latest casacore/casarest/python-casacore, for increased performance

Task #9192 and #9580 and #9581: fixes for filtering of tasks and responsiveness of loading/filtering data

Task #9192: Run pipelines with lower priority (than inspection plots etc), prevent cancellation of docker pull/tag jobs, propagate runPipeline exit code

Task #8887: merged trunk into this branch. Fixed merge conflict with JDM. skip brokon test tRATaskSpecified.py

Task #8887: added ScheduleChecker, which automatically moved scheduled pipelines just ahead of now, and which extends the endtime of running pipelines to now

Task #8892: Merged some changes in the Scheduler for CEP4 with the trunk from branch CEP4-Scheduler-Task8892

Task #8887: Reverting back to Ubuntu 14.04, C++98, and fewer optimisations, to avoid AOFlagger crash in NDPPP