Closes#876.
- Add `testMultipleSynchronizersCanRunAtOnce()` test which creates
multiple instances of the `SDKSynchronizer` and then executes sync in
parallel.
- To achieve this it's required to have multiple instances of the
lightwalletd in the darkside mode. Because of this new test is in the
new target `AliasDarksideTests`. It's little bit harder to run this
test than to run regular darkside tests. So it has it's own target.
- Fix bug when all the instances of the `SDKSynchronizer` used same data
DB even with different aliases.
- Add script to run multiple instances of the lightwalletd in
darkside mode. And add script to stop these instances and clean after
those.
- Update `DarksideWalletService` a little so the endpoint can be passed
to it. Without this it would always use default endpoint when created
with service.
- Small cleanup in `TestCoordinator`.
8e5db5e0b5