Minix editline v0.1.3

=====================

Fix another build warning for Arm cross-gcc, which actually was v4.1.2
This time getpid() was missing unistd.h, but kill() was also missing 
signal.h.  Added test for signal.h, but left out unistd.h since we
already define SYS_UNIX -- which we should really check for instead...

The rest are cosmetic prototype or automake/autoconf fixes.

src/unix.h

@@ -8,6 +8,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 #if	defined(USE_DIRENT)
 #include <dirent.h>