pgsql: Update version stamps for 8.1 as listed in RELEASE_CHANGES.

Log Message:
-----------
Update version stamps for 8.1 as listed in RELEASE_CHANGES.

Modified Files:
--------------
    pgsql/doc:
        bug.template (r1.26 -> r1.27)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/bug.template.diff?r1=1.26&r2=1.27)
    pgsql/src/interfaces/ecpg/compatlib:
        Makefile (r1.18 -> r1.19)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/compatlib/Makefile.diff?r1=1.18&r2=1.19)
    pgsql/src/interfaces/ecpg/ecpglib:
        Makefile (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/ecpglib/Makefile.diff?r1=1.29&r2=1.30)
    pgsql/src/interfaces/ecpg/pgtypeslib:
        Makefile (r1.23 -> r1.24)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/pgtypeslib/Makefile.diff?r1=1.23&r2=1.24)
    pgsql/src/interfaces/ecpg/preproc:
        Makefile (r1.110 -> r1.111)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/Makefile.diff?r1=1.110&r2=1.111)
    pgsql/src/interfaces/libpq:
        Makefile (r1.126 -> r1.127)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/Makefile.diff?r1=1.126&r2=1.127)
        libpq.rc.in (r1.2 -> r1.3)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/libpq.rc.in.diff?r1=1.2&r2=1.3)
    pgsql/src/port:
        win32ver.rc (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/win32ver.rc.diff?r1=1.5&r2=1.6)
    pgsql/src/tools:
        RELEASE_CHANGES (r1.52 -> r1.53)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/tools/RELEASE_CHANGES.diff?r1=1.52&r2=1.53)