Merge pull request #290 from bboreham/master

Quote $@ everywhere, to guard against spaces, globbing, etc.
cosmetic(ish): consistently use $(...) instead of `...`
Simplify docker version sed expression (close #282)
Merge pull request #292 from errordeveloper/fix_282

Simplify docker version sed expression

Fixes #282.
cosmetic
don't swallow error
Since sometimes the error is different from what we expect.
nodelay is the default, according to the docs
kill stale connections
The weave protocol already effectively performs heartbeating -
FetchAll is performed at regular intervals. Hence we can detect stale
connections by the lack of receiving any data for approximately that
interval (we use x2).

We use the same interval to set a time limit on the handshake too, and
any subsequent interactions prior to the connection being fully
established.

Fixes #272.
fmt