Process potential double spends as quickly as possible. (#1387)
Process potential double spends as quickly as possible. (#1387)

* Forward potential double spends as quickly as possible.

When we have a conflict, which could be a double spend, we need to notify
the commitQ thread to run immediately which also processes the deferred
queue. In this way a double spend will get processed and forwarded as
quick as possible, whearas, if we don't do this it could be up to 2 seconds
before the double spend is processed and forwarded. And then on the
next peer it could be another 2 seconds and so forth, causing double spends
to trickle slowly through the network.


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