* configure.in, acconfig.h: new files; partially functional GNU

    * configure.in, acconfig.h: new files; partially functional GNU
          autoconf configure script. Run autoheader; autoconf; ./configure
          --prefix=`pwd` to test.
        * Makefile.tmpl: new file; this is what Makefile.in used to be. Used by
          Configure.
        * Makefile.in: modified to work with autoconf-style configure script
        * Configure: modified to use Makefile.tmpl and generate autoconf-style
          macros. Removed procfs detection. Pass -O2 to gcc, -O to other
          compilers. Removed mknod/mkfifo detection; code should use mkfifo(3).
        * citmail.c, msgform.c, netproc.c, routines.c, support.c, userlist.c,
          whobbs.c: use HAVE_STRERROR macro rather than NO_STRERROR
        * commands.c: use HAVE_TERMIOS_H macro rather than POSIX_TERMIO
        * netproc.c: remove procfs stuff. simply attempt to kill the target
          process with signal zero instead; this checks whether the process
          exists.
        * setup.c, useradmin.c: use HAVE_CURSES_H macro