Gummiboot: Switch to zip archive.

For some reason tarballs from cgit have a different hash each time you download.
Merge commit 'refs/top-bases/experimental/multiple-versions-in-one-file' into experimental/multiple-versions-in-one-file

# By Shea Levy
# Via Shea Levy
* commit 'refs/top-bases/experimental/multiple-versions-in-one-file':
  Gummiboot: Switch to zip archive.
Merge branch 'master' into refs/top-bases/experimental/xsbt

# By Shea Levy
# Via Shea Levy
* master:
  Gummiboot: Switch to zip archive.
Merge branch 'experimental/multiple-versions-in-one-file' into refs/top-bases/experimental/xsbt

* experimental/multiple-versions-in-one-file:
Merge commit 'refs/top-bases/experimental/xsbt' into experimental/xsbt

# By Shea Levy
# Via Marc Weber (3) and Shea Levy (1)
* commit 'refs/top-bases/experimental/xsbt':
  Gummiboot: Switch to zip archive.