Fixes to WirelessReceiver and wl_test
Changed receive callback to use std::function so we can use std::bind topass non-static member functions. There is still a weird problem whereWirelessReceiver::dummy gets called many times for each incoming packetin wl_test.
Small changes to wireless, and starting turning with line following.
Added WirelessReceiver to libscout
It does not yet have any filtering functionality, which can be added inthe future if it's really needed.