pgsql: Support for KOI8U encoding

Log Message:
-----------
Support for KOI8U encoding

Modified Files:
--------------
pgsql/doc/src/sgml:
charset.sgml (r2.90 -> r2.91)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/charset.sgml?r1=2.90&r2=2.91)
pgsql/src/backend/utils/mb:
encnames.c (r1.37 -> r1.38)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/encnames.c?r1=1.37&r2=1.38)
wchar.c (r1.70 -> r1.71)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/wchar.c?r1=1.70&r2=1.71)
pgsql/src/backend/utils/mb/Unicode:
UCS_to_most.pl (r1.6 -> r1.7)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/Unicode/UCS_to_most.pl?r1=1.6&r2=1.7)
pgsql/src/backend/utils/mb/conversion_procs:
Makefile (r1.20 -> r1.21)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/conversion_procs/Makefile?r1=1.20&r2=1.21)
pgsql/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic:
utf8_and_cyrillic.c (r1.23 -> r1.24)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c?r1=1.23&r2=1.24)
pgsql/src/include/mb:
pg_wchar.h (r1.83 -> r1.84)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/mb/pg_wchar.h?r1=1.83&r2=1.84)
pgsql/src/port:
chklocale.c (r1.10 -> r1.11)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/port/chklocale.c?r1=1.10&r2=1.11)

Added Files:
-----------
pgsql/src/backend/utils/mb/Unicode:
koi8u_to_utf8.map (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/Unicode/koi8u_to_utf8.map?rev=1.1&content-type=text/x-cvsweb-markup)
utf8_to_koi8u.map (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/Unicode/utf8_to_koi8u.map?rev=1.1&content-type=text/x-cvsweb-markup)