- separate shared part and context part from iconv_t.
- add cache of shared part.
and, bump shlib_version minor of i18n modules because iconv i/f is changed.
add core engine of Citrus iconv and some support routines.
- iconv core (citrus_iconv)
- coded character set mapper (csmapper)
- encoding scheme database (esdb)
- standard encoding scheme handler (stdenc)
- basic character set manipulation utilities (bcs)
- mmap based infrastructure (citrus_lookup/_mmap/_memstream/_db)
- some source codes of new plugins (not built yet)