Re #7694. Moving to directory for new python api.
Re #7694. Converted to use new python api.
Re #7694. Adding a bit of wiki to LoadMultipleGSS.
Re #7128. Adding unit test for LoadMultipleGSS.
Re #7694. Comment out PythonAlgorithms install as it's gone.

The directory disappeared with the last file that was in it, leading
to an error on making the package.
Re #7694. Fixed RuntimeError message.
Merge remote-tracking branch 'origin/feature/7694_loadmultgss_pyapi'