#407 Post-Python 3: edit/submitaddpub uses a misleading evaluation function

[Ahasuerus]

edit/submitaddpub.py uses "EvalField" to check input values. It's misleading because EvalField is normally used to compare entered values against pre-existing values. However, the "Add Publication" data entry form doesn't use pre-existing values except for a few that are read-only, so there is nothing to check newly entered data against.