Fix build on RHEL7

Fixes #26

Makefile

@@ -1,4 +1,4 @@
-CFLAGS = -w -Os
+CFLAGS = -w -O
 
 CLEANFILES =				\
 	lisp				\

bestline.c

@@ -143,6 +143,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <sys/time.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>