accounts/abi/bind: surface raw wrappers to access low level ops

common: added Hash unmarshal json length validation

eth: enforce signing hashes using eth_sign instead of arbitrary data

core: homestead chain configuration & artificial gas floor target mining flag

Exposes some core methods to transition and compute new state
information and adds an additional return value to the transition db
method to fetch required gas for that particular message (excluding gas
refunds from any SSTORE[X] = 0 and SUICIDE.

Fixes #2395

The chain maker and the simulated backend now run with a homestead phase
beginning at block 0 (i.e. there's no frontier).

This commit also fixes up #2388

Added chain configuration options and write out during genesis database
insertion. If no "config" was found, nothing is written to the database.

Configurations are written on a per genesis base. This means
that any chain (which is identified by it's genesis hash) can have their
own chain settings.

accounts/abi/bind, cmd/abigen: dedup structs, exclude patterns

eth: fix accidental nil panic on nil errors

eth: manually convert errors to strings on the trace API (json cannot)

accounts/abi/bind: fix double pointer in generated code

accounts/abi/bind: Go ABI binding generator

core, core/vm, tests: changed the initialisation behaviour of the EVM

This commit serves as a temporary workaround for enabling the jit until
the block customisation PR is merged in.

Implemented the following block debugging RPC calls

* Block(RLP)
* BlockByFile(fileName)
* BlockByNumber(number)
* BlockByHash(hash)

The EVM is now initialised with an additional configured object that
allows you to turn on debugging options.

Strip extraneous carriage return from end of entered password

rpc/http: improve request handling

The EVM was previously initialised and created for every CALL, CALLCODE,
DELEGATECALL and CREATE. This PR changes this behaviour so that the same
EVM can be used through the session and beyond as long as the
Environment sticks around.

accounts/abi: Fixed bytes input accept []byte and variable input support

eth, miner: fetch pending block/state in on go (data race)

accounts/abi: handle the "constant" modifier for functions