Display mask in the InstrumentView superimposed on the data in another color

[mantid-builder]

Original Reporter: Steve Williams

It would be useful to see the mask superimposed on the counts data in the InstrumentView in another colour, like say grey. It would stop the mask from being in the wrong place letting odd stray pixels into the final results.

At the moment masked pixels show as zeros amoungst other zeros in the data.

From Richard

Re: I can make Display Mask display the masking superimposed on a sample run workspace as a diagnostic.
That would be very good!

[mantid-builder]

This issue was originally trac ticket 2720