python - be: Raise Postgres.Errors as what they are defined to be,

Log Message:
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Raise Postgres.Errors as what they are defined to be, rather than raising it as
a "Python exception occurred" with all the information in the DETAILs.
Make the exception conversion function use the current Python exception, rather
than passing in the exception variables.
Rename some static globals and make a convenient macro to initialize them.
(No need to worry about cleaning up, if these fail, it's fatal.)

Modified Files:
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be/src:
pl.c (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/pl.c.diff?r1=1.3&r2=1.4)