Connectedness was totally incorrect. added a test case.

- run the build image task every time to avoid
  running the test on stale code
- run the test from a script, so that we can
  run the test on different pre-built images.
  like:

    # build an image now and run tests on it
    make test

    # run tests on previously built image
    ./run-test-on-img.sh ipfs-stable

    # TODO: run test on git ref
    ./run-test-on-git-ref.sh <git-ref>

this commit changes how the dockertest image is built.
it moves the command into dockertest/Makefile. It also
uses a cached file that -- if removed with make clean
-- can signal whether the image should be rebuilt.
(it may be ideal to have it either detect code has
changed, or just rebuild every time. )

some dht tests signaled "sending peer empty addresses"
which would then cause a failure. this was a misrepresentation
on the part of mocknet. it has been corrected.

- Make sure we call IdentifyConn on dialed out conns
- we wait until the identify is **done** before return
- on listening case, we can also wait.
- tests now make sure dial does wait.
- tests now make sure we can wait on listening case.

this is a major refactor of the entire codebase
it changes the monolithic peer.Peer into using
a peer.ID and a peer.Peerstore.

Other changes:
- removed handshake3.
-	testutil vastly simplified peer
-	secio bugfix + debugging logs
-	testutil: RandKeyPair
-	backpressure bugfix: w.o.w.
-	peer: added hex enc/dec
-	peer: added a PeerInfo struct
  PeerInfo is a small struct used to pass around a peer with
 	a set of addresses and keys. This is not meant to be a
 	complete view of the system, but rather to model updates to
 	the peerstore. It is used by things like the routing system.
-	updated peer/queue + peerset
-	latency metrics
-	testutil: use crand for PeerID gen
 	RandPeerID generates random "valid" peer IDs. it does not
 	NEED to generate keys because it is as if we lost the key
 	right away. fine to read some randomness and hash it. to
 	generate proper keys and an ID, use:
 	  sk, pk, _ := testutil.RandKeyPair()
 	  id, _ := peer.IDFromPublicKey(pk)
 	Also added RandPeerIDFatal helper
- removed old spipe
- updated seccat
- core: cleanup initIdentity
- removed old getFromPeerList

Godeps: update dependency for go-msgio

Otherwise there is the following failure when running godep restore:

fatal: reference is not a tree: 281b085dc602c4f0377438e20331f45a91bcdf9c
godep: restore: exit status 128

License: MIT
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>

Bitswap rounds

@whyrusleeping

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

addresses...

https://github.com/jbenet/go-ipfs/pull/438/files#r21878994

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

@whyrusleeping may wanna have a look and make sure i didn't screw
anything up here

BenchmarkInstantaneousAddCat1MB-4            200          10763761 ns/op
97.42 MB/s
BenchmarkInstantaneousAddCat2MB-4       panic: runtime error: invalid
memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0xbedd]

goroutine 14297 [running]:
github.com/jbenet/go-ipfs/exchange/bitswap/decision.(*taskQueue).Remove(0xc2087553a0,
        0xc2085ef200, 0x22, 0x56f570, 0xc208367a40)
    /Users/btc/go/src/github.com/jbenet/go-ipfs/exchange/bitswap/decision/taskqueue.go:66
    +0x82
github.com/jbenet/go-ipfs/exchange/bitswap/decision.(*Engine).MessageSent(0xc20871b5c0,
        0x56f570, 0xc208367a40, 0x570040, 0xc208753d40, 0x0, 0x0)
    /Users/btc/go/src/github.com/jbenet/go-ipfs/exchange/bitswap/decision/engine.go:177
    +0x29e
github.com/jbenet/go-ipfs/exchange/bitswap.(*bitswap).send(0xc20871b7a0,
        0x56f4d8, 0xc208379800, 0x56f570, 0xc208367a40,
        0x570040, 0xc208753d40, 0x0, 0x0)
    /Users/btc/go/src/github.com/jbenet/go-ipfs/exchange/bitswap/bitswap.go:352
    +0x11c
github.com/jbenet/go-ipfs/exchange/bitswap.(*bitswap).taskWorker(0xc20871b7a0,
        0x56f4d8, 0xc208379800)
    /Users/btc/go/src/github.com/jbenet/go-ipfs/exchange/bitswap/bitswap.go:238
    +0x165
    created by
    github.com/jbenet/go-ipfs/exchange/bitswap.New
    /Users/btc/go/src/github.com/jbenet/go-ipfs/exchange/bitswap/bitswap.go:66
    +0x49e

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

in many places, entries are assigned from one slice to another and in
different goroutines. In one place, entries were modified (in the
queue). To avoid shared mutable state, probably best to handle entries
by value.

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

not changing this because i don't want to write a test for it now

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

addresses https://github.com/jbenet/go-ipfs/pull/438#discussion_r21952271

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

addresses https://github.com/jbenet/go-ipfs/pull/438#discussion_r21953742

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

only sort SortedEntries()

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

this opens up the possibility of having multiple queues. And for all
outgoing messages to be managed by the decision engine

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>

bitswap keeps the threadsafe version. observing the ledger shows that it
doesn't need it anymore (ledgermanager is protected and safe).

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>