gateway: dont cache ipns paths

ipns paths are mutable and should not be cached. this error is
a byproduct of the currently messy gateway route. We should split
the /ipfs and /ipns routes up.

ratelimiter: fixing rate limiter use

Use of the ratelimiter should be conscious of the ratelimiter's
potential closing. any loops that add work to ratelimiter
should (a) only do so if the rate limiter is not closed,
or (b) prevent limiter while work is added
(i.e. use limiter.Go(addWorkHere))

since construction can fail, and construction is non-trivial, it's
probably safer to never assume resource exists.

cc @jbenet @whyrusleeping

exposed the Decider to make configuration nicer @mappum

decalarative configuration is superior. the thread-safety because
important during normal operation

corehttp: allow all webui paths we published.

Otherwise we break users links! cc @mappum

p2p/protocol/identity: smarter tracking observed addrs

- time them out (already was doing that with addrbook)
- keep count to counter symmetric nats

routing/kbucket: fix data race

Gateway Changes

Add ipfs-test-lib.sh

add blocklist to gateway executable

log

fix main

use pointer

use func

comment on decider to clarify whether it allows or denies

fix set conf

gstw

This reverts commit bbcc86b7.

humanize is required for sharness. doh!

implement metadata node for unixfs and other

implement trickledag for faster unixfs operations