Clean up reflectometry algorithms

[Mathieu Doucet]

Since the reduction situation with REFL and REFM has evolved at SNS, it's not clear which reflectometry algorithm is actually used.

Someone needs to go through the following algorithms and decide whether they need to be removed:

1. RefLReduction.py (this is the main REFL reduction algorithm, but it hasn't been touched for 8 months. Is it still in use?)
2. RefReduction.cpp (removing this will also mean removing REFM from the reduction UI - an easy task)
3. RefRoi.cpp (this algorithm is called by RefReduction)
4. REFLReprocess.py (this algorithm was written to quickly re-reduce data files that have already been reduced. If that's not something that's used, this algorithm should probably go.)

If those algorithms are kept, they should be properly documented with an RST file and given usage examples as necessary.

There is help on how to document the algorithms in the following links: http://www.mantidproject.org/Algorithm_Documentation http://www.mantidproject.org/Algorithm_Usage_Examples And there are examples implemented for Fit, Load, LoadISISNexus and Rebin.

[Nick Draper]

Moved to R3.5 at the R3.4 code freeze

[Stuart Campbell]

This ticket has been transferred to github issue ​10479