Make HAVE_TERMIOS_H and associated config.sh shell variable available

when configure detects the presence of termios.h; later we'll use this
for correct configuration of edline/readline.

Also, fix a bug in acconfig.h -- somebody forgot to add an undef to
cover the LIBNDBM configure symbol, which was preventing autoheader
from working properly.

acconfig.h

@@ -78,6 +78,9 @@
    (e.g. void fprintf(FILE *, char *, ...);) *and* <stdarg.h> */
 #undef HAVE_STDARG_PROTOTYPES
 
+/* Define if you have termios available */
+#undef HAVE_TERMIOS_H
+
 /* Define this if you have the type uintptr_t */
 #undef HAVE_UINTPTR_T
 
@@ -169,6 +172,9 @@
 /* Define if you want to use BSD db. */
 #undef WITH_LIBDB
 
+/* Define if you want to use ndbm. */
+#undef WITH_LIBNDBM
+
 /* Define if you want to produce an OpenStep/Rhapsody framework
    (shared library plus accessory files). */
 #undef WITH_NEXT_FRAMEWORK

configure.in

@@ -406,7 +406,7 @@ dnl AC_MSG_RESULT($cpp_type)
 # checks for header files
 AC_HEADER_STDC
 AC_CHECK_HEADERS(dlfcn.h fcntl.h limits.h locale.h ncurses.h poll.h pthread.h \
-signal.h stdarg.h stddef.h stdlib.h thread.h unistd.h utime.h \
+signal.h stdarg.h stddef.h stdlib.h thread.h unistd.h utime.h termios.h \
 sys/audioio.h sys/file.h sys/lock.h db_185.h db.h \
 sys/param.h sys/select.h sys/socket.h sys/time.h sys/times.h \
 sys/un.h sys/utsname.h sys/wait.h pty.h libutil.h \