If a seednode is using netwlayer version 0.6.2 (or 0.6.1) it is not
reachable from other nodes. Still unclear what causes that and if it
would affect also normal Bisq nodes, but to be careful we revert to
latest stable netlayer version which fixes the issue.
We used checkpoint files from BitcoinJ 0.14.4 and those caused a very
slow initial download. I tested with the WalletAppKit and different
release version sof BitcoinJ and could reproduce the behaviour there.
WIth v0.14.5 it was much better. But also that caused slow startup in
Bisq. After creating a current checkpoint file and using that the
download is now very fast.
Also added logging for versions of BitcoinJ and libDohJ so that we have
better control which version is used.
This performs the same function that the maven-enforcer-plugin did in
the pom removed by the previous commit, and also includes a more
comprehensive / up-to-date set of dependencies.
Note that the gradle-witness jar checked in here is one built from the
pull request in signalapp/gradle-witness#26.
