update cluster setup for -discovery

fix issues with peer-addr when using bind-all (0.0.0.0) for binding.
moves more config switches out of template and into helper lib.
adding a way to override how you want ot name the instance.
add etcd.addr attribute for -addr value on bind.

when running with -bind-addr=0.0.0.0 theetcd instance will respond with redirects to 127.0.0.1 unless this is set
return empty string when local disabled

bug where we would return nil when local was disabled
fixup kitchen
update specs
update to pass specs
update readme
Merge pull request #21 from spheromak/cluster_cleanup

Cluster cleanup