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_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

containers: regroup and add Alpine images (31 MB)

internal/debug: APIs for profiling and tracing

core, core/types, miner: fix transaction nonce-price combo sort

The debug package provides an RPC wrapper for glog settings and the
debugging facilities of the Go runtime. They can be triggered through
both command line flags and the IPC listener.

The "result" field of JSON-RPC 2.0 responses was omitted
if the result was nil, causing exceptions in web3.js.

Rpc2 console

logger/glog: improve vmodule