
Loads given handler in table of handlers bound to encoding specified in the
handler, using ISO 639 and RFC 1766 language IDs of the handler as keys for future table lookups.
If another handler was already specified for given RFC 1766 id, table entry
will be updated and will refer to new handler. If another handler was already
specified for given ISO 639 id, it will be replaced only if new handler has
ISO 639 language ID equal to its RFC 1766 ID.
Please do not load custom versions of @x-any@ and @x-ftq-x-any@ handlers.