* cm.c (tputs, tgoto, BC, UP): Remove extern decls. Include
tparam.h instead, since it declares them.
* cm.h (PC): Remove extern decl; tparam.h now does this.
* deps.mk (cm.o, terminfo.o): Depend on tparam.h.
* terminfo.c: Include tparam.h, to check interfaces.
(tparm): Make 1st arg a const pointer in decl. Put it at top level.
(tparam): Adjust signature to match interface in tparam.h;
this removes some undefined behavior. Check that outstring and len
are zero, which they always are with Emacs.
* tparam.h (PC, BC, UP): New extern decls.
* term.c, tparam.h: Include it.
* deps.mk (term.o, tparam.o): Depend on tparam.h.
* term.c (tputs, tgetent, tgetflag, tgetnum, tparam, tgetstr):
Move these decls to tparam.h, and make them agree with what
is actually in tparam.c. The previous trick of using incompatible
decls in different modules does not conform to the C standard.
All callers of tparam changed to use tparam's actual API.
* tparam.c (tparam1, tparam, tgoto):
Use const pointers where appropriate.
