pgsql: Simplify psql's new linestyle behavior to default to

Log Message:
-----------
Simplify psql's new linestyle behavior to default to linestyle=ascii all
the time, rather than hoping we can tell whether the terminal supports
UTF8 characters. Per discussion.

Modified Files:
--------------
pgsql/doc/src/sgml/ref:
psql-ref.sgml (r1.234 -> r1.235)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/psql-ref.sgml?r1=1.234&r2=1.235)
pgsql/doc/src/sgml:
release-8.5.sgml (r1.6 -> r1.7)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release-8.5.sgml?r1=1.6&r2=1.7)
pgsql/src/bin/psql:
mbprint.c (r1.36 -> r1.37)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/mbprint.c?r1=1.36&r2=1.37)
mbprint.h (r1.14 -> r1.15)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/mbprint.h?r1=1.14&r2=1.15)
print.c (r1.118 -> r1.119)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/print.c?r1=1.118&r2=1.119)
pgsql/src/test/regress:
pg_regress_main.c (r1.7 -> r1.8)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/pg_regress_main.c?r1=1.7&r2=1.8)