pgsql: Remove tabs from SGML files to help tag alingment and improve

Log Message:
-----------
Remove tabs from SGML files to help tag alingment and improve
detection of tabs are added in the future.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        docguide.sgml (r1.70 -> r1.71)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/docguide.sgml.diff?r1=1.70&r2=1.71)
        ecpg.sgml (r1.80 -> r1.81)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ecpg.sgml.diff?r1=1.80&r2=1.81)
        func.sgml (r1.359 -> r1.360)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml.diff?r1=1.359&r2=1.360)
        geqo.sgml (r1.38 -> r1.39)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/geqo.sgml.diff?r1=1.38&r2=1.39)
        gin.sgml (r2.10 -> r2.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/gin.sgml.diff?r1=2.10&r2=2.11)
        libpq.sgml (r1.229 -> r1.230)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/libpq.sgml.diff?r1=1.229&r2=1.230)
        mvcc.sgml (r2.67 -> r2.68)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/mvcc.sgml.diff?r1=2.67&r2=2.68)
        plperl.sgml (r2.63 -> r2.64)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/plperl.sgml.diff?r1=2.63&r2=2.64)
        sql.sgml (r1.45 -> r1.46)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/sql.sgml.diff?r1=1.45&r2=1.46)