Board renders, but only when touched. Tray and scoreboard skipped for
now. Lots of changed still to go, and some asserts added where I didn't
want to stop to solve a compile problem.
for Rematch): works for linux version, provided you know the relayID
of the device you're inviting. Added to common/ a stream-saving
version of java's NetLaunchInfo I'll probably want to use there too
for cross-platform compatibility (there being no jni support for
json.)
