peerstream would hang when it got many temporary errors.
temp errors should not count as an error. Now, it will
only exit when an error is not temporary.

I kept the acceptErr channel because it will no longer
cause a bad hang. The goroutine is exiting, so if it
blocks until acceptErr is read, it's fine. If users
launch tons of listers and see goroutines building up,
they know they should be reading + logging those.

Instead of erroring out, which would break the listener,
we instead log a message and continue. This is not an error,
the internet is a place with lots of probing + connection
failures.

This should handle early breakages, where a failing connection
would take out the listener entirely.

There are probably other errors we should be handling here,
like secure connection failures.

Implement ipfs ping

core: make sure to call swarm.FilterAddrs

also move network setup into its own self-contained func

linkblock size calc test

osxfuse: fix version check

fix ping test

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

Conflicts:
	core/commands/root.go

begin ping command, WIP

finish initial ping implementation

benchmark Sign and Verify operations

BenchmarkSign1B             1000           2406924 ns/op
BenchmarkSign10B            1000           2360527 ns/op
BenchmarkSign100B           1000           2354136 ns/op
BenchmarkSign1000B           500           2361775 ns/op
BenchmarkSign10000B          500           2415993 ns/op
BenchmarkSign100000B         500           2718051 ns/op
BenchmarkVerify1B          30000             52117 ns/op
BenchmarkVerify10B         30000             50968 ns/op
BenchmarkVerify100B        30000             51037 ns/op
BenchmarkVerify1000B       30000             56768 ns/op
BenchmarkVerify10000B      10000            105744 ns/op
BenchmarkVerify100000B      2000            628530 ns/op

install-sharness.sh: use git instead of wget and shasum

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

path: ignore prefix /ipfs/

gc closed conns

Fix test_docker Makefile target and rename it test_3node

```
2015/01/07 21:57:16 COPY has been deprecated. Please use ADD instead
```

Thanks @inconshreveable