eth, eth/downloader, eth/fetcher: delete eth/61 sync code

eth/api: rename signAndSendTransaction to sendTransaction

The eth/61 protocol was disabled in #2776, this commit removes its
message handlers and hash-chain sync logic.

containers/docker: update to alpine 3.4

eth: cancel DAO challenge on peer drop (annoying log)

Godeps: bump github.com/syndtr/goleveldb/... to ab8b5dcf104

Fix #2710 Filter race: concurrent map read and map write

cmd/bootnode: Add support for outputting a node's ID on the command line

eth: fixed chaindb upgrade

cmd, core, eth, miner, params, tests: finalize the DAO fork

circleci: enable docker based hive testing

vm: Replace some SstoreClearGas with SstoreResetGas

Godeps, rpc: switch back to package npipe

This adds compatibility with Go 1.7, where context has
moved into the standard library.

The named pipe implementation from go-winio has some issues
that need to be addressed before we can use it again.

core: added CheckNonce() to Message interface

eth/downloader: return invalid chain (peer drop) on import fails

core: solve a remote-import/local-mine data race

README: expand with "Running Geth" section