refs #8125. class for getting the latest runs.

Max's original gui has windows, hard-coded and commented out code to do this. I've redone this in a separate class, as we may end up replacing it in the future anyway with ICAT.
refs #8125. Renamed to settings.xml
refs #8125. Hook-up the LatestISISRuns utility.

Have a fall-back in case a settings file is not present, or cannot be read. In these cases we do not want to crash-out.
refs #8125. Make robust against white space.

I've just tested this out on both Windows7 and OSX and the feature works wit the DataMountPoint. Will still need to log an error if for some reason the settings cannot be imported. Will also need further manual testing.
refs #8125. Better error reporting.

Exceptions relating to settings and archive directories are logged. Execution is allowed to continue normally. Better error reporting messages have been provided.
refs #8125. More flexibility for LatestISISRuns.

LatestISISRuns can fetch run information for an instrument across many cycles (disabled by default). It also has a new method to quickly calculate what cycles are available to select runs from. This method will be used as a way of providing more advanced inputs.

Made it possible to use the GUI without mantid plot by disabling the plotting aspects if mantid plot cannot be imported.
refs #8125. Handle cycles for each instrument.

Allow switching between cycles for a single instrument. Display cycles to choose from. Update cycles when instrument is changed. Default to latest cycle and load run names.

Also set it up so that it extracts the run number from the workspaces as part of the transfer process so that only run number rather than workspace names appear in the table.
refs #8125. Hide and show the cycles widget as appropriate.
refs #8125. Fix failing test.

Statement moved outside of try-except block
refs #8125. Fix merge conflicts.