Merge pull request #136 from gotoalberto/feesfix

Add support for fees
Add CoinffeineConnectionStatus events
Convert BitcoinConnectionStatusWidget in ConnectionStatusWidget

Make this class to display both Bitcoin and Coinffeine connection
information.

Introduce CombinedConnectionStatus to combine both connection statuses
into a color and a textual description and reduce the responsibilities
of ConnectionStatusWidget.
Merge pull request #137 from sortega/task/163_widget

Show in the status bar both bitcoin and coinffeine connection status
Rename PaymentProcessor to FeeCalculator
Make order actor consider the fees while blocking fiat funds
Make CoinffeineWallet.currentBalance() and Option[BitcoinAmount]

This is needed to represent unavailable bitcoin balances.
Integrate OkPayFeeCalculator into PaymentProcessor
Merge pull request #138 from gotoalberto/task/175

Make order actor consider the fees while blocking fiat funds
Remove unused code
Make CoinffeinePeerActor retrieve connection status

The information is retrieved from the message gateway and the bitcoin
peer.
Avoid unnecessary message gateway creations on ProtoMessageGatewayTest
Make ProtoMessageGateway able to report connection status
Make BitcoinPeerActor honor RetriveConnectionStatus

And fix a potential problem: state were mutated on a future.
Do not wait for a successful connection to start the app
Merge pull request #140 from sortega/task/158_connection

Do not wait for a successful connection to start the app