This is to avoid having to import ds elsewhere.

config: rename addresses

Rather than pushing errors back down to lower layers, propagate the
errors upward.

This commit adds a `ReceiveError` method to BitSwap's network receiver.

Still TODO: rm the error return value from:

    net.service.handler.HandleMessage

This is inspired by delegation patterns in found in the wild.

WARNING: change breaks old configs.
@whyrusleeping @perfmode

This commit changes the way addresses are stored in config files.
It lumps Identity.Address and RPCAddress into Addresses. This
commit also fixes several golint issues.

This commit...

is a second attempt at: https://github.com/jbenet/go-ipfs/pull/68

partially addresses: https://github.com/jbenet/go-ipfs/issues/66

is the result of discussion at:

    https://gist.github.com/perfmode/f2951c1ed3a02c484d0b

Fixed Ping (minor)

Fixed a link in the README (and capitalization).

This fixes the broken pinging. (the issue was the cluster
level, it's bein set incorrectly (off by one))

Anyway, this works now:

    [peer: QmfQTbC3LxfpK5WoyHW2WgnAzo6d6GePuq2wHTsJNXM5PS] Sent message type: 'PING' [to = QmNXUeFrV9gxR4aqJddEsfhWZLSJrUsfpUSeRb3R7xvSp9]
    [QmfQTbC3LxfpK5WoyHW2WgnAzo6d6GePuq2wHTsJNXM5PS] ping QmNXUeFrV9gxR4aqJddEsfhWZLSJrUsfpUSeRb3R7xvSp9 end (err = %!s(<nil>))

cc @whyrusleeping

New net interface

failing due to nil pointer dereference

sending

true -> always send to peer

false -> use ledger-based strategy described in IPFS paper draft 3

fix(bitswap) pass go vet

fixes #97

https://github.com/jbenet/go-ipfs/issues/97

until construction is complete on the actual async method

reverts changes from ec50703395098f75946f0bad01816cc54ab18a58

https://github.com/jbenet/go-ipfs/commit/ec50703395098f75946f0bad01816cc54ab18a58

changing the bitswap interace breaks tests and makes things a bit
difficult going forward. I think I have a temporary solution to replace
the async method.

this commit partially reverts changes from:

ec50703395098f75946f0bad01816cc54ab18a58

https://github.com/jbenet/go-ipfs/commit/ec50703395098f75946f0bad01816cc54ab18a58

@jbenet

Handshake library has been modified to use Secure Pipe. This test
targets the old implementation.

TODO: write a new handshake test

@perfmode using non-async version as apparently there's
a bug in async. will look into it.