Restraint from Mogul (CSD) export failing

[briantoby]

Import of a .csv file from Mogul fails with this error:

Traceback (most recent call last):
  File ~/G2/git/g2full/GSAS-II/GSASII/GSASIIrestrGUI.py:246 in OnUseMogul
    AddMogulBondRestraint(restrData['Bond'])
  File ~/G2/git/g2full/GSAS-II/GSASII/GSASIIrestrGUI.py:358 in AddMogulBondRestraint
    oInd = Names.index(oName)
ValueError: 'O1' is not in list

[briantoby]

Problem turns out to be that an atom was renamed in the GSAS-II atoms list, so O1 could not be found. A test for this along with a more user-friendly error message was introduced in 51deecf