Deformed Preferences for Query Computation in Protege 5.0

The implementation of #51 (closed) introduces a redesign of the preference page for query computation.

It does look as intended in Protege 5.1:

whereas the page is deformed in Protege 5.0 (probably of using a class of protege that has changed in 5.1):

Todo: check for the version of Protege and fall back to a compatible layout for Protege 5.0