Retransmit timing changes
Retransmit timing changes

- makes it behave more like in the description
- partial for #847

bmng-dev/PyBitmessage,hb9kns/PyBitmessage,bmng-dev/PyBitmessage,hb9kns/PyBitmessage,hb9kns/PyBitmessage,bmng-dev/PyBitmessage,hb9kns/PyBitmessage