Merge pull request #308 from apoloval/task/cf-100

Make preferences form to save the settings
Make BlockedFiatRegistry a persistent actor
Move BlockedFiatRegistry to its own package
Extract MultipleBalance from BlockedFiatRegistry

It manages the details of updating a balance in several currencies.
Extract BlockedFundsAvailability from BlockedFiatRegistry

This class replaces three member variables that were used for tracking
blocked funds availability.
Reduce nesting in BlockedFiatRegistryTest

After moving the blocked funds id generation out of the actor we don’t
need to use the load pattern and avoid nesting.
Make BlockedFiatRegistry notify after recovery
Test OkPayProcessorActor in isolation

Mock its delegate actor to avoid testing both OkPayProcessorActor and
its delegate BlockedFiatRegistry.
Merge pull request #309 from sortega/issue/108_persist_fiat_funds

Persist fiat funds blocking
Require an exchange id when blocking bitcoins
Use ExchangeId instead of BlockedCoinsId
Remove Exchange.BlockedFunds

Now that both fiat and bitcoin funds are blocked using the exchange
identifier this piece of information is useless.
Improve FundsBlocker.Listener

After changing the result type from Try[BlockedCoinsId] to Try[Unit] it
is easier to have onSuccess/onFailure methods. Propagate the change to
the OrderController classes.
BlockedOutputs rejects blocking twice for an id
Improve integration tests logs

Improve formatting of some messages that are logged, avoid logging a
whole exchange when just its id will do. Also avoid logging when unit
testing the ChaosMessageGateway and saving 5k lines of scroll.
Merge pull request #311 from sortega/improve_logging

Improve integration tests logs
Merge pull request #310 from sortega/issue/109_refactor_blocked_coins

Changes preparing for persistent bitcoin funds blocking