Added loadbby unit test. re #9394

And renamed property "Hdf Reference" to "HdfReference" to satisfy http://builds.mantidproject.org/job/develop_systemtests_rhel6/lastCompletedBuild/testReport/SystemTests/CodeConventions/Algorithms/
(tx to martyn for spotting this)
Merge branch 'feature/9394_loader_bilby_' into develop