core/vm: JIT segmentation

eth/63 fast synchronization algorithm

core, tests: get_hash fix

Make sure that we're fetching the hash from the current chain and not
the canonical chain.

core, core/state: move gas tracking out of core/state

The amount of gas available for tx execution was tracked in the
StateObject representing the coinbase account. This commit makes the gas
counter a separate type in package core, which avoids unintended
consequences of intertwining the counter with state logic.

* multi-push segments
* static jumps segments

Moved the execution of instructions to the instruction it self. This
will allow for specialised instructions (e.g. segments) to be execution
in the same manner as regular instructions.

core, eth/filters, miner, xeth: Optimised log filtering

Log filtering is now using a MIPmap like approach where addresses of
logs are added to a mapped bloom bin. The current levels for the MIP are
in ranges of 1.000.000, 500.000, 100.000, 50.000, 1.000. Logs are
therefor filtered in batches of 1.000.

godeps: update ethash following GPU miner merge

all: Add GPU mining, disabled by default

core/state, core, miner: handle missing root error from state.New

Update libsecp256k1, Go wrapper and tests

core, eth, event, miner, xeth: fix event post / subscription race

common, crypto: add ICAP functions

core/vm: copy stack element to prevent overwrites

cmd, core, eth: added official testnet

cmd: properly initialize Olympic for all subcommands