Move source back into correct place in RRO for release v3.6.0

Apply background correction

Merge pull request #15149 from mantidproject/15146_change_forceRootDirScripts_and_update_documentation

PowderDiffraction:: forceRootDirFromScripts default value changed & Doc updated - for release-v.3.6.0

Refs #15136

Refs #15136

Refs #15136

refs #15146

LR geometry fix

Fix building docs-qthelp with newer sphinx.

Looks OK to me. 

Fix crash in InstrumentView when adding Peak

This covers the case when there are 0 peaks in the PeaksWorkspace, which I had forgotten about earlier.

Porting SCD interface document from the wiki

Fix SpaceGroupFactoryTest for rhel6 

Merge pull request #15110 from mantidproject/15071_further_improvements_to_workflow_ISIS_Powder_Diffraction

ISIS Powder Diffraction:: Further Improvements To The Workflow 

Fix windows paths in LoadCIF

Michael Wedel authored Jan 28, 2016 and Peterson, Peter committed Jan 29, 2016

Instead of not registering the algorithm at all, the import is now checked when the algorithm is executed and produces an error that guides the user to the right python package to install. The intention of this is to enable building of documentation. Otherwise users wouldn't have any way of knowing that this algorithm exists.

Fix CMP0026 warning with Xcode generator.

Fix API::Bool from returning a double

Instead of not registering the algorithm at all, the import is now checked when the algorithm is executed and produces an error that guides the user to the right python package to install. The intention of this is to enable building of documentation. Otherwise users wouldn't have any way of knowing that this algorithm exists.