remove node AP reference pointer when timing out nodes
parse BlockAck src and dst address
only update MODE if it was unknown or PROBE
Show probe request ESSID
add new control command outfile=X
dont listen on stdin in quiet mode

This fixes a bug when select always returned, causing CPU load 100%
Improve control pipe reading

- Parse multiple commands
- Allow sending multiple commands (-x command1:command2:command3)
- Sender side waits for pipe to exist
- Simplify select handling by using "rw" (no close needed)
Improve log strings