* Rewrite a bunch of the hack/ directory with modular reusable bash libraries.
* Have 'build/*' build on 'hack/*'. The stuff in build now just runs hack/* in a docker container.
* Use a docker data container to enable faster incremental builds.
* Standardize output to _output/{local,dockerized}/bin/OS/ARCH/*. This regularized placement makes cross compilation work.
* Move travis specific scripts under hack/travis
With new dockerized incremental builds, I can do a no-op `make quick-release` in ~30s. This is a significant improvement.
The pause image is a 240KB image that simply pauses waiting on a signal.
Use this for the net container which only needs to act as a placeholder.
Current net image is ~2.5MB. From my tests, this reduces startup time
for the net container from ~14s to ~6s.
Dawn Chen