This contains significant rebase / merge / testing work by Naut
<lbrynaut@protonmail.com>, Anthony Fieroni <bvbfan@abv.bg> and Brannon
King <countprimes@gmail.com>.
This should fix the spurious comparison tool failures.
See discussion here: https://github.com/bitcoin/bitcoin/pull/6305
The race fix was cherry-picked on top of the version we're currently using, so
it should be functionally identical otherwise.
This should be functionally identical to what's in place now. It was built from
be0eef7744
That commit is the same as this pruned commit in TheBlueMatt's repo:
https://github.com/TheBlueMatt/bitcoinj/commit/0f7b5d8
Now we'll be able to trust the line numbers in the stack traces.
