[#73607174] Package etcd version 0.4.6

Package etcd, a highly-available key value store for shared configuration and service discovery. I'm planning to use this in conjunction with locksmith to coordinate automatic reboots:

https://github.com/coreos/locksmith

This build is for Trusty, but since it's a Go binary with almost no dependencies, we can use the same binary for Precise.
I doubt it build-depends on git (given launchpad doesn't allow outbound network access)