Add documentation to Stitch command for ORNL SANS

[Mathieu Doucet]

The ORNL SANS command "Stitch" doesn't have documentation when you do help(Stitch).

[Mathieu Doucet]

Re #7990 add help doc

Changeset: 55cf5670c0759e05176a1fa7beb73b3a005fa35a

[Mathieu Doucet]

Re #7990 catch more error conditions

Changeset: 1d2732914046ac0a742a28adb12c4038dc60e7eb

[Mathieu Doucet]

To test:

• Check that the stitching works by trying to stitch SANS data from the reference results directory. Executing the following script should load and scale the data. It should also produce a new workspace named 'stitched' with the stitched result. It should also write a file 'stitched.xml' in your default output directory in Mantid.

  import os
  from reduction_workflow.instruments.sans.sns_command_interface import *
  data_dir = "~git/systemtests/SystemTests/AnalysisTests/ReferenceResults/"
  data_list = [os.path.join(data_dir, "HFIRReduction.nxs"),
               os.path.join(data_dir, "EQSANSIQOutput.nxs") ]
  Stitch(data_list, 0.04, 0.06, 'stitched', 2.0, True)
  

• Check that documentation is available by doing:

  from reduction_workflow.instruments.sans.sns_command_interface import *
  help(Stitch) 
  

[Samuel Jackson]

Merge remote-tracking branch 'origin/feature/7990_SANS_Stitch_Doc'

[Samuel Jackson]

Stitch does what it's supposed to do and documentation is shown when running help().

[Stuart Campbell]

This ticket has been transferred to github issue ​8835