Pending logs are now filterable through the Go API. Filter API changed
such that each filter type has it's own bucket and adding filter
explicitly requires you specify the bucket to put it in.

account/abi, vm/runtime: abi fixes & simplified runtime calling mechanism

Implemented `runtime.Call` which uses - unlike Execute - the given state
for the execution and the address of the contract you wish to execute.
Unlike `Execute`, `Call` requires a config.

Removed old unmarshalling of return types: `abi.Call(...).([]byte)`.
This is now replaced by a new syntax:

```
var a []byte
err := abi.Call(&a, ...)
```

It also addresses a few issues with Bytes and Strings and can also
handle both fixed and arbitrary sized byte slices, including strings.

eth: Added GPO to suggest default gas prices

eth, eth/downloader, jsre: surface state sync progress through the API

This PR fixes a regression of the RPC where the default gas price that
was being used for transaction wasn't properly using the GPO. This PR
adds the GPO back to suggest gas prices rather than the hardcoded
default of 10000000000000.

Closes #2194

eth, miner: move the public miner api into eth to access etherbase

eth/downloader: raise pending state limit that prevented concurrency

eth_sendTransaction, error not reported

eth/filters: added notifications for out of bound log events

Out of Bound log events are events that were removed due to a fork. When
logs are received the filtering mechanism should check for the `removed`
field on the json structure.

cmd/utils: fix jspath flag typo

cmd, common, node, rpc: move IPC into the node itself

rpc: add jsonrpc version to module request, use json types

rpc: allow RPC requests on GET too

core/state, trie: don't leak database writes before commit

cmd, eth, rpc: fix some RPC issues with pending blocks

core/vm, rpc/api: added debug_replayTransaction RPC call

account/abi: implements event parsing

CONTRIBUTING: Added a feature section

miner: register newly created remote agent in the API

Implementation of basic event parsing and its input types. This
separates methods and events and fixes an issue with go type parsing and
validation.

Integrated code review suggestions

Integrated last review comments

core, eth, rpc/api: rpc method to inspect the txpool queue

p2p/discover: fix Windows-specific issue for larger-than-buffer packets

containers/docker/master-alpine: add the legacy gmp lib back for now