* [DEV-97] Moved github.com/daglabs/btcutil into github.com/daglabs/btcd/btcutil.
* [DEV-97] Updated Gopkg.toml to no longer refer to btcutil.
* [DEV-97] Renamed btcutil to util.
* [DEV-62] add phantom constructs to blocknode
* [DEV-62] add phantom constructs to blocknode
* [DEV-72] write blues()
* [DEV-72] write blues()
* [DEV-72] write blues()
* [DEV-62] add comments to new phantom constructs in blocknode
* Fixed dbIndexConnectBlock. (#33)
* Fixed dbIndexConnectBlock.
* Removed redundant check in storeFilter.
* Created a new method to BlockHeader: IsGenesis.
* [DEV-71] Implement BlockHeap (#35)
* [DEV-71] Implemented BlockHeap.
* [DEV-71] Removed irrelevant comment.
* [DEV-71] Renamed variables in Pop() and split Less() to multiple lines.
* [DEV-72] write blues()
* [DEV-72] write blues()
* [DEV-72] write blues()
* [DEV-72] write blues tests
* [DEV-72] write blues tests
* [DEV-72] remove relevant past
* [DEV-72] write blues tests
* [DEV-72] write blues tests
* [DEV-72] write blues tests
* [DEV-72] write functions to order blockSet by hash and write blue tests
* [DEV-72] add secret mining and censorship attack tests
* [DEV-72] remove prints
* [DEV-72] remove K from dagconfig.Params
* [DEV-72] remove K from dagconfig.Params
* [DEV-72] change blueScore to uint64
* [DEV-72] block V was missing, so renamed w -> v, x -> w etc
* [DEV-72] use node.String instead of %v
* [DEV-72] block V was missing, so renamed w -> v, x -> w etc
* [DEV-72] add K to dagconfig.Params, and add expected reds to all phantom tests
* [DEV-72] set K=10 and add comments to phantom and phantom tests
* [DEV-72] fix formatting and add comments to TestPhantom
* [DEV-72] fix grammar
