* libc/include/wchar.h: Declare wcstol, wcstoll, wcstoul,

	* libc/include/wchar.h: Declare wcstol, wcstoll, wcstoul,
	wcstoull, _wcstol_r, _wcstoll_r, _wcstoul_r and _wcstoull_r.
	* libc/stdlib/Makefile.am (GENERAL_SOURCES): Add wcstol.c and wcstoul.c.
	(EXTENDED_SOURCES): Add wcstoll.c, wcstoll_r.c, wcstoull.c and
	wcstoull_r.c.
	(CHEWOUT_FILES): Add .def files accordingly.
	* libc/stdlib/Makefile.in: Regenerate.
	* libc/stdlib/stdlib.tex: Add documentation links for above functions.
	* libc/stdlib/strtoll.c: Fix portability note.
	* libc/stdlib/strtoull.c: Ditto.
	* libc/stdlib/wcstol.c: New file.
	* libc/stdlib/wcstoll.c: New file.
	* libc/stdlib/wcstoll_r.c: New file.
	* libc/stdlib/wcstoul.c: New file.
	* libc/stdlib/wcstoull.c: New file.
	* libc/stdlib/wcstoull_r.c: New file.