build a static cockroach binary

edit: latest update at the bottom.


* added a `make build_static`
* vendored in everything that was left: bz2, zlib, protobuf
* build only static libs
* light brushing up of the Dockerfile

next up: a small Cockroach deploy image, built after successful tests through CircleCI.
Ah I got you. That wasn't immediately obvious. A comment here and where the tests are run that they're not part of the deploy container would be helpful.