Add a version number search to the downloads

[TellowKrinkle]

The only way to get to a specific build number in the current interface is to mash page buttons, jumping 20 builds at a time. Not great if you need a build from 1000 builds ago, which is often required for bisecting.

Instead, a way to search for a specific build number would be nice

[TellowKrinkle]

The ability to get a link to the download page of a specific build would be nice as well