More vicious disrupter
Also delete trade listing key when trade complete
New trading strategy

Creates as many combined trades as possible.
Tracks multiple in-progress combined trades & tries to finish any of them.
Cleans up all after the first finishes.

This strategy is efficient when some trade partners are slower than others.
However it is quite spammy and might not scale so well.

Unit test status: mock dht code works, TomP2P fails.
Fixed disrupter code, added new broken unit test
More readable debug output
Unit tests are now completely deterministic