Refs #9041 Fixed bug with coadding workspaces

There was a problem where you couldn't comma or colon delimit workspaces in the runs column as the workspaces were overwriting each other. Unrelated to this ticket, but it prevented me from continuing so it had to be fixed in this ticket.

Code/Mantid/scripts/Reflectometry/isis_reflectometry/convert_to_wavelength.py

@@ -45,7 +45,9 @@ def to_workspace(cls, candidate):
             if  mantid.api.AnalysisDataService.doesExist(candidate.strip()):
                 _workspace = mantid.api.AnalysisDataService.retrieve(candidate.strip())
             else:
-                 _workspace = msi.Load(Filename=candidate)
+                ws_name = "_" + str(candidate.strip())
+                msi.Load(Filename=candidate, OutputWorkspace=ws_name)
+                _workspace = mantid.api.AnalysisDataService.retrieve(ws_name)
         else:
              raise ValueError("Unknown source item %s" % candidate)
         return _workspace
@@ -55,7 +57,6 @@ def __to_workspace_list(self, source_list):
         for item in source_list:
             temp.append(ConvertToWavelength.to_workspace(item))
         self.__ws_list = temp
-
 
     def __init__(self, source):
         """