Selecting an entity in one part of the hierarchy locks down any entities beneath it

[tg137]

An example would be selecting an entire dataset and afterwards being unable to select the datafiles within that dataset.

This has been discussed and would cause problems with datasets with a large number of datafiles where you would have to iterate through each datafile and add it to the basket.

I am therefore marking it as wontfix.

[jodysalt]

#295 might provide a more intuative alternative for bulk selection