This adds Bazel/hscloud integration to gostatic, via gostatic_tarball.
A sample is provided in //tools/gostatic/example, it can be built using:
bazel build //tools/gostatic/example
The resulting tarball can then be extracted and viewed in a web
browser.
Change-Id: Idf8d4a8e0ee3a5ae07f7449a25909478c2d8b105