pointer-based newlib implementation.
(_ctype_b): Declare.
(__ctype_cp): Move to newlib. Declare.
(__ctype_iso): Ditto.
(__set_ctype): Implement changing __ctype_ptr__. Only copy character
class data in applications built under older Cygwin.
* cygwin.din (__ctype_ptr__): Export.
* include/ctype.h: Remove in favor of newlib implementation.
* include/cygwin/config.h (__EXPORT): Define alongside __IMPORT.
* include/cygwin/version.h (CYGWIN_VERSION_CHECK_FOR_OLD_CTYPE):
Define check for old vs. new ctype implementation.
Bump API minor number.
(__ctype_default): New character class array for default ASCII
character set.
(__ctype_iso): New array of character class array for ISO charsets.
(__ctype_cp): Ditto for singlebyte Windows codepages.
(tolower): Implement as distinct function to support any singlebyte
charset.
(toupper): Ditto.
(__set_ctype): New function to copy singlebyte character classes
corresponding to current charset to ctype_b array.
Align copyright text to upstream.
* dcrt0.cc (dll_crt0_1): Reset current locale to "C" per POSIX.
* environ.cc (set_file_api_mode): Remove.
(codepage_init): Remove.
(parse_thing): Remove "codepage" setting.
(environ_init): Set locale according to environment settings, or
to current codepage, before converting environment to multibyte.
* fhandler.h (fhandler_console::write_replacement_char): Drop argument.
* fhandler_console.cc (dev_console::str_to_con): Call sys_cp_mbstowcs
rather than MultiByteToWideChar.
(fhandler_console::write_replacement_char): Always print a funny
half filled square if a character isn't in the current charset.
(fhandler_console::write_normal): Convert to using __mbtowc
rather than next_char.
* fork.cc (frok::child): Drop call to set_file_api_mode.
* globals.cc (enum codepage_type) Remove.
(current_codepage): Remove.
* miscfuncs.cc (cygwin_wcslwr): Unused, dangerous. Remove.
(cygwin_wcsupr): Ditto.
(is_cp_multibyte): Remove.
(next_char): Remove.
* miscfuncs.h (is_cp_multibyte): Drop declaration.
(next_char): Ditto.
* strfuncs.cc (get_cp): Remove.
(__db_wctomb): New function to implement _wctomb_r functionality for
doublebyte charsets using WideCharToMultiByte.
(__sjis_wctomb): New function to replace unusable newlib function.
(__jis_wctomb): Ditto.
(__eucjp_wctomb): Ditto.
(__gbk_wctomb): New function.
(__kr_wctomb): Ditto.
(__big5_wctomb): Ditto.
(__db_mbtowc): New function to implement _mbtowc_r functionality for
doublebyte charsets using MultiByteToWideChar.
(__sjis_mbtowc): New function to replace unusable newlib function.
(__jis_mbtowc): Ditto.
(__eucjp_mbtowc): Ditto.
(__gbk_mbtowc): New function.
(__kr_mbtowc): New function
(__big5_mbtowc): New function
(__set_charset_from_codepage): New function.
(sys_wcstombs): Reimplement, basically using same wide char to multibyte
conversion as newlib's application level functions. Plus extras.
Add lengthy comment to explain. Change return type to size_t.
(sys_wcstombs_alloc): Just use sys_wcstombs. Change return type to
size_t.
(sys_cp_mbstowcs): Replace sys_mbstowcs, take additional codepage
argument. Explain why. Change return type to size_t.
(sys_mbstowcs_alloc): Just use sys_mbstowcs. Change return type to
size_t.
* wchar.h: Declare internal functions implemented in strfuncs.cc.
(wcscasecmp): Remove.
(wcsncasecmp): Remove.
(wcslwr): Remove.
(wcsupr): Remove.
* winsup.h (codepage_init): Remove declaration.
(get_cp): Ditto.
(sys_wcstombs): Align declaration to new implementation.
(sys_wcstombs_alloc): Ditto.
(sys_cp_mbstowcs): Add declaration.
(sys_mbstowcs): Define as inline function.
(sys_mbstowcs_alloc): Align declaration to new implementation.
(set_file_api_mode): Remove declaration.
* include/ctype.h (isblank): Redefine to use _B character class.
(toupper): Remove ASCII-only definition.
(tolower): Ditto.
