Various fixes.

B - fixed usage, DISPLAY :0 vs :0.0
	9term - fixed various terminal things
	rc - notice traps in Read
	_p9dir - only run disk code for disks
	dirread - getdirentries on FreeBSD and Linux
		are different w.r.t. meaning of off.
	notify - set up so signals interrupt system calls
	bprint - use bfmt.

src/cmd/9term/FreeBSD.c

@@ -13,6 +13,5 @@ getchildwd(int pid, char *wdir, int bufn)
 int
 getpts(int fd[], char *slave)
 {
-	openpty(&fd[1], &fd[0], slave, 0, 0);
-	return 0;
+	return openpty(&fd[1], &fd[0], slave, 0, 0);
 }