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

Change number of args passed to NewIterator in print function to reflect changes in the goleveldb project.