Add more aliases for Hebrew and Arabic ISO-8859-... encodings.

ISO-8859-8 is supposed to be visual order (i.e. legible if displayed ltr)
ISO-8859-8-i is supposed to be implicit logic order
ISO-8859-8-e is supposed to be explicit about order

In practice, ISO-8859-8 implying visual order is rare, and logic
order is used. ISO-8859-8-e is rarely used.

Same for Arabic, which uses ISO-8859-6-...

Mentioned in RFC 1555, RFC 1556.

(maya)