transitional ethutil.ReadConfig fixes in ethchain tests (they still fail! FIXME :)
Merge pull request #27 from ethersphere/bugfix/ethchain-test

transitional ethutil.ReadConfig fixes in ethchain tests (they still fail...
move ethutil helper slice functions -> slice
move ethutil hex conversion functions to bytes
move ethutil helper crypto functions to ethcrypto/crypto
move ethutil/mnemonic to ethcrypto - electrum word list now sourced from file
config Pubkey removed (unused)
remove ethutil helpers (refactored), and keypair (key management under ethcrypto package)
Key Manager
- keypair, keyring:
-- consistent naming of methods
-- error propagation
-- no panic
- keyManager: persist, import, export, initialize and (re)set keyring
- no global public "singleton" keyring, instead interface via keyManager
- keys test
- KeyStore interface, DB and File store implementations