tests: add tests for ecdsa.verify
crypto: remove Hmac* exposure in API
crypto: re-work fixtures for simplicity
HDNode: move var declaration out of branches
all: remove deprecated functionality
Wallet: fix impl. and tests after deprecated APIs removed
HDNode: remove toBuffer/toHex
Transaction/TxBuilder: move all param coercion to TxBuilder
remove Wallet
Transaction/RawTx: renames TxBuilder to Transaction
RawTransaction: re-order functions to project standard
RawTransaction: rename tmpTx to tx
tests: remove unnecessary test

This functionality is tested already through the fixtures.
RawTransaction: avoid statement repetition

ECMAScript guarantees order of execution of object literal expressions
in the order they are written.
ECKey: use pubKey over pub
ECPair: replaces ECKey/ECPubKey