pgsql: Stamp release 7.3.15.

Log Message:
-----------
Stamp release 7.3.15.

Tags:
----
REL7_3_STABLE

Modified Files:
--------------
    pgsql:
        configure (r1.226.2.25 -> r1.226.2.26)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/configure.diff?r1=1.226.2.25&r2=1.226.2.26)
        configure.in (r1.217.2.23 -> r1.217.2.24)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/configure.in.diff?r1=1.217.2.23&r2=1.217.2.24)
    pgsql/doc:
        bug.template (r1.21.2.16 -> r1.21.2.17)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/bug.template.diff?r1=1.21.2.16&r2=1.21.2.17)