refs #9569. Expose CatalogManager.

Add python tests for new behaviour
refs #9569. Expose CatalogSessions and test.
refs #9569. Use ICAT in ReflGUI.

Have added extra options on the options dialog to enable/disable this, but have not wired everythin in yet. Will also need to uncomment and test that the old code still works.
refs #9569. Allow switchable behaviour.

Warn if ICAT search without ICAT download.

Enable the Journal searching as the default.
refs #9569. Fix merge conflict and other errors.

Merge branch 'master' into feature/9569_icat_for_refl

Conflicts:
	Code/Mantid/scripts/Interface/ui/reflectometer/refl_gui.py
refs #9569. Return const ref to fix test failure.

Tests now seem to run correctly on windows. The const ref must have been
used to extend the lifetime of the member variable!
Merge branch 'feature/9569_icat_for_refl' into develop