Обсуждение: python - ex: Add code specific classes and generalize IntegrityError.

Log Message:
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Add code specific classes and generalize IntegrityError.
Add Undefined* and Duplicate* code specific exceptions. These are likely to be
fairly common, so provide use convenience by giving code specific exceptions.

IntegrityError has become an abstract exception; ICV code class is now bound to
the ICVError exception, which inherits from IntegrityError.

Other minor changes.

Modified Files:
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    ex/src:
        prime.py (r1.6 -> r1.7)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/ex/src/prime.py.diff?r1=1.6&r2=1.7)