Fixed rate limiting problem with api.blockcypher.com.

Fixed a problem when requesting many bitcoin addresses where the blockcypher.com API limits the number of requests to 3 requests/second.

Fixed issue with native segwit addresses

Fetches Bitcoin quantity for addresses now via api.blockcypher.com API, because it can handle native segwit addresses.

Signed Update

Fixed fetching the bitcoin price in EUR by using https://blockchain.info/ticker. It's a free API which requires no APIKey or Password.