(Vcharset_ucs_bmp): New variable in UTF-2000.

(Vcharset_ucs_bmp): New variable in UTF-2000.
(charset_by_attributes): Delete array about direction.
(latin_a_char_to_charset): New variable.
(latin_a_char_to_byte1): New variable.
(latin_a_char_to_byte2): New variable.
(leading_code_private_11): Don't define in UTF-2000.
(Qucs_bmp): New variable.
(next_allocated_1_byte_leading_byte): Use `Charset_ID' instead of
`Bufbyte'.
(next_allocated_2_byte_leading_byte): Likewise.
(non_ascii_set_charptr_emchar): Likewise.
(make_charset): Likewise; add `CHARSET_TYPE_128X128' and
`CHARSET_TYPE_256X256' in UTF-2000; modify for
`charset_by_attributes'.
(get_unallocated_leading_byte): Use `Charset_ID' instead of
`int'.
(char-charset): Use `CHAR_CHARSET' instead of `CHAR_LEADING_BYTE' and
`CHARSET_BY_LEADING_BYTE'.
(syms_of_mule_charset): Set up `ucs-bmp'; move setting of
`utf-2000-version' to `vars_of_mule_charset'.
(vars_of_mule_charset): Modify for `charset_by_attributes'; don't
define `leading-code-private-11' in UTF-2000; move setting of
`utf-2000-version' from `syms_of_mule_charset'.
(complex_vars_of_mule_charset): Set up charset `ucs-bmp' in UTF-2000.