pgsql-server: Remove more traces of libpgtcl from the source tree.

Log Message:
-----------
Remove more traces of libpgtcl from the source tree. Also, make some
semi-related SGML cleanup. Original patch from ljb220@mindspring.com,
additional cleanup by Neil Conway.

Modified Files:
--------------
    pgsql-server:
        README (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/README.diff?r1=1.29&r2=1.30)
        configure (r1.396 -> r1.397)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/configure.diff?r1=1.396&r2=1.397)
        configure.in (r1.378 -> r1.379)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/configure.in.diff?r1=1.378&r2=1.379)
    pgsql-server/doc/src/sgml:
        installation.sgml (r1.204 -> r1.205)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/installation.sgml.diff?r1=1.204&r2=1.205)
        release.sgml (r1.297 -> r1.298)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/release.sgml.diff?r1=1.297&r2=1.298)
    pgsql-server/doc/src/sgml/ref:
        create_function.sgml (r1.61 -> r1.62)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/ref/create_function.sgml.diff?r1=1.61&r2=1.62)

Removed Files:
-------------
    pgsql-server/doc/src/sgml/ref:
        pgtclsh.sgml
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/ref/pgtclsh.sgml)