Re #6807. Add log warning on unfulfilled request for historical data.

If an event-based live listener does not support historical data, then
tell the user that they're only going to be getting data from the
algorithm launch time onwards.
Re #6807. Use non-stream logger for fixed string.

Also set the start time to zero rather than the current time, for
consistency with what's done above. The end result will be the same.
Re #6807. Make comments more general.

The previous comments don't belong in this general class as they were
talking about very specific SNS/ADARA/SMS things.
Re #6807. Correct the supportsHistory value on the SNS listener.
Re #9541. Precursor: Fix indentation issues.
Re #9541. Add a monitor workspace member to MatrixWorkspace.

Along with simple getter, setter and test.
Re #9541. Add a test of the factory behaviour.

The workspace factory should not propagate monitor workspaces.
Re #9541. Add ExtractMonitorWorkspace algorithm and test.
Re #8342. Add a run number getter to the live listener interface.

This allows a concrete live listener to return the current run number.
Previously, there was a hack in place that tried to fetch it out of
the extracted workspace, but this only worked for MatrixWorkspace (it
used the getRunNumber method). This way will work for any kind of
returned workspace.

Currently, listeners that do not have the capability of obtaining a
run number will always return zero. This also happens to the value
returned by the SNS listener when an instrument is not in a run (though
there's also the runStatus method that will indicate this).

Concrete listeners remain responsible for adding the run number to the
workspace logs, if appropriate.
Re #8342. Forgot to fill in a method.
Re #9541. Correct doxygen omission.
Merge branch 'feature/6807_livedata_supportshistory_check' into develop
Merge branch 'feature/8342_run_number_in_livelistener_interface' into develop
Merge branch 'feature/9541_matrixws_monitorws_member' into develop