Status: Work in progress

Clients can set their own client string which will be send to connected
peers during the handshake.

The Ethereum structure now complies to a EthManager interface which is
being used by the tx pool, block manager and block chain in order to
gain access to each other. It's become simpeler.
TODO: BlockManager => StateManager

Rename .travil.yml to .travis.yml

Conflicts:
	ethdb/database.go