* cygheap.cc (cygheap_init): Default locale.charset to "UTF-8".

	* cygheap.cc (cygheap_init): Default locale.charset to "UTF-8".
	* dcrt0.cc (dll_crt0_1): Call setlocale (LC_CTYPE, "") here, just
	before resetting application locale to "C".
	* environ.cc (environ_init): Drop code setting locale here.
	* syscalls.cc (check_codepage): Break out check for required codepage
	from internal_setlocale.
	(internal_setlocale): Just convert CWD and $PATH from old charset to
	new charset and set internal charset.
	(setlocale): Change accordingly.  Don't require LC_ALL or LC_CTYPE to
	store old locale value.  Always call internal_setlocale if charset
	changed due to locale environment changes.