first usable version of kernel and commands

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

sys/src/lib/auth/auth_getkey.c

@@ -0,0 +1,51 @@
+#include <u.h>
+#include <libc.h>
+#include <auth.h>
+
+int
+auth_getkey(char *params)
+{
+	char *name;
+	Dir *d;
+	int pid;
+	Waitmsg *w;
+
+	/* start /factotum to query for a key */
+	name = "/factotum";
+	d = dirstat(name);
+	if(d == nil){
+		name = "/boot/factotum";
+		d = dirstat(name);
+	}
+	if(d == nil){
+		werrstr("auth_getkey: no /factotum or /boot/factotum: didn't get key %s", params);
+		return -1;
+	}
+if(0)	if(d->type != '/'){
+		werrstr("auth_getkey: /factotum may be bad: didn't get key %s", params);
+		return -1;
+	}
+	switch(pid = fork()){
+	case -1:
+		werrstr("can't fork for %s: %r", name);
+		return -1;
+	case 0:
+		execl(name, "getkey", "-g", params, nil);
+		exits(0);
+	default:
+		for(;;){
+			w = wait();
+			if(w == nil)
+				break;
+			if(w->pid == pid){
+				if(w->msg[0] != '\0'){
+					free(w);
+					return -1;
+				}
+				free(w);
+				return 0;
+			}
+		}
+	}
+	return 0;
+}