first usable version of kernel and commands

After an year of hard work, this is a first "usable" version of Jehanne.

qa/kern/fork.c

@@ -0,0 +1,36 @@
+/*
+ * This file is part of the UCB release of Plan 9. It is subject to the license
+ * terms in the LICENSE file found in the top-level directory of this
+ * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
+ * part of the UCB release of Plan 9, including this file, may be copied,
+ * modified, propagated, or distributed except according to the terms contained
+ * in the LICENSE file.
+ */
+
+#include <u.h>
+#include <libc.h>
+
+void
+main(void)
+{
+	static int c;
+	int pid;
+	pid = rfork(RFMEM|RFPROC);
+	if (pid < 0) {
+		print("FAIL: rfork\n");
+		exits("FAIL");
+	}
+	if (pid > 0) {
+		c++;
+	}
+	if (pid == 0) {
+		print("PASS\n");
+		exits("PASS");
+	}
+
+	if (c > 1) {
+		print("FAIL\n");
+		exits("FAIL");
+	}
+	exits("PASS");
+}