Add an empty/none marker option in pyplot.plot()

Merge pull request #16010 from mantidproject/15950_documentation_for_pearl_powder_diffraction_script

Documentation for Pearl powder diffraction script

Refs #15965 LoadBBY and PatchBBY now support monochromatic neutrons

Fix bug with complement rule parsing in Object::procString

System test for Pearl powder diffraction script

refs #15950

Make constructor explicit.

Fixes new cppcheck warning with v1.7.3

The SANS centre finding algorithms uses the object XML to mask
parts of the instrument. The fixes have slightly affected the
pixels that are masked but not to any significant degree.

Indirect OSIRIS Diffraction - Add OSIRIS_GSS_Parameter file to instrument dir

Inelastic Support for MonteCarloAbsorption algorithm

Default extension in powder diffraction interface 

Correct the bad example of FitPeak in doc test

refs #15950

refs #15950

refs #15950

Integrate a FitPropertyBrowser and a DisplayCurveFit in the BackgroundRemover interface

Remove memory leak in UsageService

Assign the correct rule number when passing a single rule to
Object::procPair. The method detected that only one rule was present
correctly but failed to tell the external code which one it had found.
This led to the rule map being updated incorrectly.

The commit also switches the order in which the rules are assigned in
Intersection constructor to be consistent with the rest of the class
and the Union operation.

refs #15913

refs #15950

refs #15950

refs #15950

refs #15950

GSL2 test tolerances

refs #15950

Indirect Bayes Quasi - EMin / EMax range bars update on data load

Fix compiler warning in ObjCompAssemblyActor for debug build