pgsql: Have pgcvslog mark back-branch commits with "<back-patch>".

Log Message:
-----------
Have pgcvslog mark back-branch commits with "<back-patch>".

Modified Files:
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pgsql/src/tools:
pgcvslog (r1.33 -> r1.34)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/pgcvslog?r1=1.33&amp;r2=1.34)