The DHCP server broadcasts messages. This are being sent via the
default netif which might be completely the wrong network. We want to
send messages to the netif we got the original message from.
Now LWIP_PLATFORM_ASSERT has been fixed we're seeing an assert for the
ping example app.
It sets the SO_RCVTIMEO socket option which is not enabled.
Fixes#308
* Add an example for how to enable TLS verification.
TLS should really be used with verification enabled, as otherwise you
can still suffer from a "man in the middle" attack. Add an example that
demonstrates how to do this.
Fixes#337
