GDA-5956 Sort out shutting down ScanDataPointPipeline
GDA-5805 - Allow use of tab for autocomplete

Changes:
-tab will offer same behaviour as ctrl+space
-both tab and ctrl-space will offer autocomplete even if word is not first (or last) word on line
-tab will insert tab only if caret is after only whitespace
-shift-tab will dedent if caret is after tab (and before all text)
-space, enter and tab will all accept currently selected option (not just top option as before)
Add keyboard interupt for keys ctrl-d and ctrl-z

-Allows users to escape partially completed multiline blocks without executing them
-Also temporary workaround to GDA-5352 until Jython fix is submitted
GDA-5970 Account for visits without a comment
Merge branch 'master' of ssh://dascgitolite@dasc-git.diamond.ac.uk/gda/gda-core.git
Merge branch 'master' of ssh://dasc-git.diamond.ac.uk/gda/gda-core
Prevent EventService returning unconfigured instance
Let Jython console display indentation errors
Merge remote-tracking branch 'origin/8.39'

Conflicts:
	uk.ac.gda.core/src/gda/scan/ScanBase.java