pgsql-server: Some preliminary documentation for composite-type stuff.

Log Message:
-----------
Some preliminary documentation for composite-type stuff.

Modified Files:
--------------
    pgsql-server/doc/src/sgml:
        array.sgml (r1.34 -> r1.35)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/array.sgml.diff?r1=1.34&r2=1.35)
        catalogs.sgml (r2.85 -> r2.86)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/catalogs.sgml.diff?r1=2.85&r2=2.86)
        datatype.sgml (r1.144 -> r1.145)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/datatype.sgml.diff?r1=1.144&r2=1.145)
        extend.sgml (r1.27 -> r1.28)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/extend.sgml.diff?r1=1.27&r2=1.28)
        filelist.sgml (r1.37 -> r1.38)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/filelist.sgml.diff?r1=1.37&r2=1.38)
        syntax.sgml (r1.92 -> r1.93)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/syntax.sgml.diff?r1=1.92&r2=1.93)

Added Files:
-----------
    pgsql-server/doc/src/sgml:
        rowtypes.sgml (r2.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/rowtypes.sgml?rev=2.1&content-type=text/x-cvsweb-markup)