Cleanup of end2end
Cleanup of end2end

- Make ping/pong into objects
- Do app setup before timeouts start, so that path lookup failures are
  obvious
- Stop spawned SCIONDaemons after each test
- Log to file and console, use logging for all output

Fixes issue where end2end would fail if ran immediately after SCION
startup.

dmpiergiacomo/scion,dmpiergiacomo/scion,klausman/scion,klausman/scion,FR4NK-W/osourced-scion,FR4NK-W/osourced-scion,Oncilla/scion,dmpiergiacomo/scion,Oncilla/scion,FR4NK-W/osourced-scion,netsec-ethz/scion,klausman/scion,netsec-ethz/scion,FR4NK-W/osourced-scion,netsec-ethz/scion,Oncilla/scion,netsec-ethz/scion,klausman/scion,Oncilla/scion,FR4NK-W/osourced-scion,dmpiergiacomo/scion,dmpiergiacomo/scion,dmpiergiacomo/scion,klausman/scion