fix fuse mounting issues

This commit moves the record validation/verification
from dht/ into the new record/ packaage. Validator object
-- which is merely a map of ValidatorFuncs -- with a
VerifyRecord

cc @whyrusleeping

this time, without loading the private key on every startup

feat(bitswap.decision.Engine) use PriorityQueue for Engine.Outbox

	refactor: peerRequestQueue

	it's a mistake to make one queue to fit all. Go's lack of algebraic
	types turns a generalized queue into a monstrosity of type
	checking/casting. Better to have individual queues for individual
	purposes.

	Conflicts:
		exchange/bitswap/decision/bench_test.go
		exchange/bitswap/decision/tasks/task_queue.go

	fix(bitswap.decision.PRQ): if peers match, always return result of pri comparison

	fix(bitswap.decision.Engine): push to the queue before notifying

	TOCTOU bug

	1. client notifies
	2. worker checks (finds nil)
	3. worker sleeps
	3. client pushes (worker missed the update)

	test(PQ): improve documentation and add test

	test(bitswap.decision.Engine): handling received messages

	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>

Conflicts:
	exchange/bitswap/decision/taskqueue.go

feat(core) replace config.Config with repo.Repo

@jbenet cool with this?

This declarative style is simpler to compose than the imperative wiring
up of objects.

+ pass context to StartOnlineServices as parameter. one by one, trying
to remove dependencies on node state so these initialization steps can
be broken down.

@jbenet wasn't sure about the terminology here. I'm certain what I wrote
is not entirely correct. Feel free to edit.

@whyrusleeping @jbenet does passing this argument effectively instruct
the dagbuilder to pin recursively?

cc @jbenet @whyrusleeping

move generic packages to thirdparty (see thirdparty/README.md)

core/mount: make non-darwin archs see fuseversion

See the note:

// this file is only here to prevent go src tools (like godep) from
// thinking fuseversion is not a required package by non-darwin archs.

basic reprovider implementation

addr-explosion mitigated adding