Merge pull request #344 from apoloval/fix/funds-widgets

New aspect for balance widgets
Wait for actor system termination in CoinffeineApp.stop()
Fix KeyPairSerializer

It was not serializing the private key for deterministic key pairs.
Improve assert message in BlockchainStatus
Add a disabled integration test for crashing recovery

Buyer and seller are restarted at random points of time and the
exchange is supposed to continue as nothing happened.
Merge pull request #345 from sortega/issue/114_test

Towards crash testing
Fix IT problem in OpenOrdersTest

The timeout for checking that the order reached the market is too short
in the case of losing the message from the broker reporting open orders.
Merge pull request #346 from sortega/fix_it

Fix IT problem in OpenOrdersTest
Require PeerId to have a hex value up to 40 digits

This guarantees compatibility of PeerId with TomP2P’s Number160.
Make the peer id a start argument of CoinffeinePeerActor
Make peer id be saved in the user configuration file
Merge pull request #347 from sortega/issue/114_test

Use stable peer ids