Fix regression in 0.12.3 where artifacts without an explicit configuration wouldn't be listed in ivy.xml.
Docs: fix broken link on nightly builds
Add google analytics tracking to sbt documentation, so we can see which topics people are most interested in and better organize things.
Remove env subproject, which hasn't been built or published in many releases.
build with 0.12.4-RC2
Invalidate cache when metadata came from ProjectResolver. Based on the core idea in #770 by @ezh.

Fixes #768, closes #770, fixes #773.
0.13.0-Beta2