Add BIP39/44 functionality

Self Explanatory.. :)

[vampyren]

Sorry i dont think this is very "Self Explanatory"
So i found this info:
BIP-0039:
This BIP describes the implementation of a mnemonic code or mnemonic sentence -- a group of easy to remember words -- for the generation of deterministic wallets.

BIP-0044:
This BIP defines a logical hierarchy for deterministic wallets based on an algorithm described in BIP-0032 (BIP32 from now on) and purpose scheme described in BIP-0043 (BIP43 from now on).

[Warrows]

See #956

[random-zebra]

Bip44 implemented in #1327
Bip39 will not be implemented in its current form.