Fix some 8-bit-graphic characters.

Fix some 8-bit-graphic characters.
Use iso2022 encoding.
(latin1-char-displayable-p): Doc fix.
(latin1-display-ucs-per-lynx): New option.
(latin1-display-ucs-per-lynx): New command.
(latin1-display-reset): Special-case arabic.
(ucs-tables): Require.
(latin1-display-sets, latin1-display-setup): Add arabic.
(latin1-display) <variable>: Use function latin1-display.
(latin1-display) <function>: Add mule-unicode stuff.
(latin1-display-check-font): Don't lose if `info' is nil.