python - pq: Remove superfluous fatality state.

Log Message:
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Remove superfluous fatality state. Failed covers this area well enough.
However, compensate a bit for the removal by adding a 'fatal' property to
client3.Transaction that identifies failed transactions that got an error
message with a severity of 'FATAL'.

Note, even 'failed' could probably be removed as the success of the operation is
pretty much dependent on the existence of the 'exc_info' or 'error' attribute.

Modified Files:
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pq/src:
client3.py (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/pq/src/client3.py.diff?r1=1.3&r2=1.4)
transam.py (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/pq/src/transam.py.diff?r1=1.2&r2=1.3)