make dns resolution work in weave container
by using go's internal DNS resolver.

NB: this relies on go's std library having been compiled with the
netgo build tag, e.g.

   sudo go install -tags netgo -a std

issue #93
check that the go stdlib was built with the required options
AFAICT, go build tags are a compile-time only construct, so there is
no way to query whether a certain package was built with a specific
tag. However, the 'netgo' tag triggers conditional compilation of the
cgo_stubs.go file, and that file name ends up in the executable. (we
could have looked for specific symbols in the 'net.a' library instead,
but that requires locating it first, which is more hassle than it is
worth)

issue #93
Resolve name to IP address when removing connected targets
Revert "Resolve name to IP address when removing connected targets"

This reverts commit eef311ba6980183e204eda0b85b40d350aa97dd2.
Resolve peer names to IP address at startup
reformat
Change README to say that hostnames are allowed on the commandline
Merge pull request #111 from zettio/93_fqdn_peers

permit peers to be specified by name - fixes #93