refs #6865 Initial changes to possible q-frame options
refs #6865 Should allow user to choose a frame of interest in Q3D mode
refs #6865 This should fix it

e.g. enabled explicit selection of QFrame. A but more tests is still needed.
refs #6855 This should fix it

exposing Q-frame property to the algorithm interface
refs #6855 peculiar conflict on branch change (does not affect master)

Merge branch 'feature/6855_ExplicitQFrame' of https://github.com/mantidproject/mantid into develop

Conflicts:
	Code/Mantid/Framework/MDAlgorithms/inc/MantidMDAlgorithms/ConvertToMD.h