* miscfuncs.h (transform_chars): Declare. Define inline variation here.

	* miscfuncs.h (transform_chars): Declare.  Define inline variation here.
	* mount.cc (mount_info::from_fstab): Remove extern declaration of
	transform_chars.
	* path.cc (tfx_chars): Move to strfuncs.cc.
	(transform_chars): Ditto.
	* strfunc.cc (tfx_chars): Moved here from path.cc.
	(transform_chars): Ditto.
	(sys_cp_wcstombs): Make UNICODE private use area conversion roundtrip
	save for all characters.
	(sys_cp_mbstowcs): Ditto, by removing special case for UTF-8 sequences
	representing U+f0XX UNICODE chars.  Fix typo in comment.