Warn the person doing a release that what you're about to release does not belong to the product it was built for

When adding builds into a release, users need to know if the build does not belong to the product he's creating the release for.
Right now, if I add a build that does not belong to the product we're releasing into, there's no clear indication about it, see:


In order for us to release it into our product, the build needs to be added to the product (builds can belong to many products already), which can be done by going into the build page and manually adding it into a build, see:


I'd say that we should:
* Indicate the user that the build that was just added to the release does not belong to the product
* Maybe, allow the user to directly add the build to the product within the new release page

Another option would be to make this transparent to the user and directly add the build to the product when added into a release. In any case, this needs further analysis/discussion with the rest of the team and our users.