* wide_path.h (class wide_path): New class to convert Windows path

	* wide_path.h (class wide_path): New class to convert Windows path
	to WCHAR win32 path, including long path conversion if necessary.
	* cygcheck.cc: Use class wide_path throughout to call Win32 functions
	taking potentially long filenames.
	(display_error): Use snprintf rather than sprintf.
	(display_error_fmt): Ditto.
	(dump_sysinfo): Use FindFirstFileW/FindNextFileW.
	* cygpath.cc: Use class wide_path throughout to call Win32 functions
	taking potentially long filenames.
	(get_device_name): Raise buffer size to take long pathnames.
	(get_short_paths): Convert to using GetShortPathNameW.
	(get_short_name): Ditto.
	(get_long_path_name_w32impl): Convert to equivalent of GetLongPathNameW.
	(get_long_name): Convert to using GetLongPathNameW.
	(do_sysfolders): Raise buffer size for POSIX pathname to PATH_MAX.
	(do_pathconv): In case of POSIX->Win32 conversion, convert to wchar_t
	Win32 path name and drop long pathname prefix if possible.
	(main): Call setlocale to accommodate wide char/multibyte conversions.