New translation objects

[agjohnson]

I'm not yet sure how this plays with our project based translations, and maybe it's just supplementary, but translations shouldn't have to be a project-level object. On a base project, you should be able to just select the languages you want to build for, similar to versions.

Having a setting on a single project makes it far easier to manage translations, so i think this could help manage translations better. This also maps to transifex and friends, in case we do an integration to grab project translation completion/etc.

On a trigger of a new build, this would create a new build for each language that is enabled -- again, this would be similar to versions.

Some of the changes required here:

• user_build output needs to change to allow for language level as well
• Or we make a new path for symlinks (we're avoiding new features that require symlinking i believe). This could be an intermediate step to switching over docs to new pattern though
• Builds need to know about language now as well. This would be used for deduplication of builds on (build, version, language)
• Build output shows translation language

I think there is a lot more here as well. Feel free to add to this list.

[agjohnson]

Duplicate of #810