removed pty.h. minimal system guessing added in config.mk.

diff --cc config.mk
index 216e7dfd5c2bf2ca1ada1043ed6a08add6e57dbe,216e7dfd5c2bf2ca1ada1043ed6a08add6e57dbe..b41a949c4c0f57715f9c02c2867010d5541b6bd3
--- 1/config.mk
--- 2/config.mk
+++ b/config.mk
@@@ -14,7 -14,7 +14,8 @@@ X11LIB = /usr/X11R6/li
  INCS = -I. -I/usr/include -I${X11INC}
  LIBS = -L/usr/lib -lc -L${X11LIB} -lX11 -lutil
  
--# uncomment your system #
++# uncomment manualy your system if compilation fail
++SYSTEM = -D`uname | tr a-z A-Z`
  #SYSTEM = -DLINUX
  #SYSTEM = -DOPENBSD
  #SYSTEM = -DFREEBSD