Expose I_ constants. Auto-detect stropts.h. Properly configure the slave terminal.
diff --git a/configure b/configure
index 86d9578..f9121ec 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
#! /bin/sh
-# From configure.in Revision: 1.381 .
+# From configure.in Revision: 1.382 .
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.53 for python 2.3.
#
@@ -3977,9 +3977,11 @@
+
for ac_header in dlfcn.h fcntl.h grp.h limits.h langinfo.h \
libintl.h locale.h ncurses.h poll.h pthread.h \
-signal.h stdarg.h stddef.h stdlib.h thread.h unistd.h utime.h termios.h \
+signal.h stdarg.h stddef.h stdlib.h stropts.h termios.h thread.h \
+unistd.h utime.h \
sys/audioio.h sys/file.h sys/lock.h sys/mkdev.h sys/modem.h \
sys/param.h sys/poll.h sys/select.h sys/socket.h sys/time.h sys/times.h \
sys/un.h sys/utsname.h sys/wait.h pty.h term.h libutil.h \