prevent NAT check if given nil multiaddr
Merge pull request #285 from jbenet/bugfix/284

prevent NAT check if given nil multiaddr
added random to godeps
test: install random from vendored code
test: moved installed things into own dirs

I moved installed things into own dirs bin and lib.

@chriscool sorry to move things around again, the top level
test dir was getting a bit clutterd.
test/t0040-add-and-cat updated hashes (new random)
vendor: updated random + fixed test import

There is a dummy test import: test/lib/random-dep.go
Because godep doen't yet vendor binaries nicely.
Merge pull request #289 from jbenet/update-random-sharness-tests

Update random for test/
write a few package doc strings to improve look of godoc
some more docs
update the readme
some net docs
copy handshake readme into a doc.go for pretty godoc results
work on readme
docs(exchange)