[rfa/readline] remove hacks for partial multibyte support

[Michael Elizabeth Chastain]

Yippee!

Committed.

gdb HEAD ought to build on native hppa2.0w-hp-hpux11.11 now,
with gcc, ansi c, or aCC.

Michael C

 > 2003-12-11  Michael Chastain  <mec.gnu@mindspring.com>
 > 
 > 	* rlmbutil.h: Require HAVE_MBSTATE_T for HANDLE_MULTIBYTE.
 > 	Revert requirement of HAVE_MBRTOWC.  Delete macro definitions
 > 	that attempted to fake mbstate_t if HAVE_MBSRTOCWS is defined
 > 	and HAVE_MBSTATE_T is not defined.
 >