* path.h (get_nt_native_path): Add third parameter to declaration and

	* path.h (get_nt_native_path): Add third parameter to declaration and
	declare with regparms.
	* path.cc (get_nt_native_path): Add third parameter to allow conversion
	of leading and trailing dots and spaces on filesystems only supporting
	filenames following DOS rules.
	(path_conv::get_nt_native_path): Call get_nt_native_path according to
	fs.has_dos_filenames_only flag.
	(getfileattr): Accommodate new parameter to get_nt_native_path.
	(symlink_info::check): Revamp fs_update_called handling to call
	fs.update only once per call.  Call get_nt_native_path according to
	fs.has_dos_filenames_only flag.  Streamline filesystem dependent code
	not to be called more than once unnecessarily.  Drop code tweaking
	incoming path for broken filesystems only allowing DOS pathnames.
	Rely on changed get_nt_native_path instead.
	* mount.cc (fillout_mntent): Accommodate new parameter to
	get_nt_native_path.
	* strfuncs.cc (tfx_rev_chars): New conversion table with comment.
	(sys_cp_wcstombs): Use tfx_rev_chars rather than tfx_chars.