pgsql: Add tools/find_gt_lt to find < and > in SGML source.

Log Message:
-----------
Add tools/find_gt_lt to find < and > in SGML source.

Lowercase some uppercase tags so tools is more reliable at finding
problems.

Tags:
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REL8_0_STABLE

Modified Files:
--------------
pgsql/doc/src/sgml:
client-auth.sgml (r1.70 -> r1.70.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/client-auth.sgml.diff?r1=1.70&r2=1.70.4.1)
contacts.sgml (r1.5 -> r1.5.12.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/contacts.sgml.diff?r1=1.5&r2=1.5.12.1)
installation.sgml (r1.228 -> r1.228.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/installation.sgml.diff?r1=1.228&r2=1.228.4.1)
protocol.sgml (r1.57 -> r1.57.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/protocol.sgml.diff?r1=1.57&r2=1.57.4.1)
release.sgml (r1.321.4.2 -> r1.321.4.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml.diff?r1=1.321.4.2&r2=1.321.4.3)
rules.sgml (r1.37.4.2 -> r1.37.4.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/rules.sgml.diff?r1=1.37.4.2&r2=1.37.4.3)
runtime.sgml (r1.301.4.1 -> r1.301.4.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/runtime.sgml.diff?r1=1.301.4.1&r2=1.301.4.2)
xindex.sgml (r1.37 -> r1.37.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/xindex.sgml.diff?r1=1.37&r2=1.37.4.1)
xoper.sgml (r1.32 -> r1.32.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/xoper.sgml.diff?r1=1.32&r2=1.32.4.1)
pgsql/doc/src/sgml/ref:
pg_restore.sgml (r1.49 -> r1.49.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_restore.sgml.diff?r1=1.49&r2=1.49.4.1)
pgsql/src/tools:
RELEASE_CHANGES (r1.52 -> r1.52.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/RELEASE_CHANGES.diff?r1=1.52&r2=1.52.4.1)