patch [big]: fixed Japanese converters

Hi

By attached patch I wish to correct behaviour of Unicode 
converters for Japanese encoding schemes, and to add lacking ones.


iso2022jp.pl / iso2022jp.h:
  - JIS X 0208 mapping has been updated based on latest 
    regional standard (JIS X 0208:1997) and some vendor 
    standards.
  - Errorneous (lacking or false) mappings has been fixed.
  - Support for older JIS X 0208 (JIS C 6226:1978) mapping was 
    added.
  - JIS X 0212:1990 mapping was added.

iso2022jp.c:
  - Converters became (upper-)compatible with ISO-2022-JP 
    (RFC1468 / JIS X 0208:1997 Annex 2) and ISO-2022-JP-1 
    (RFC2237).
  - Buffer overflow vulnerability (when Unicode character is out 
    of BMP range) has been closed.
  - Convert error handling was implemented.

shiftjis.c:
  - Broken SHIFT_JIS converters has been fixed and became 
    (upper-)compatible with Shifted Encoding Method 
    (JIS X 0208:1997 Annex 1).
  - Buffer overflow vulnerability (when Unicode character is out 
    of BMP range) has been closed.
  - Convert error handling was implemented.

eucjp.c (new file):
  - New converters for EUC-JP.


  --- nezumi