Update release script with proper support for non-*.docker.io bucket URLs
Update release script to move https://get.docker.io/ubuntu/info to https://get.docker.io/ubuntu/ and provide a backwards-compatibility redirect (same for /builds/info)
Fix the display of get.docker.io in Firefox by making our index files text/plain
Merge pull request #2612 from tianon/release-script-tweaks

* Hack: release script tweaks