fixes bug 1021520 by unlinking the builds report

unlinks the nightly builds report from the UI and removes the URL route so the page cannot be accessed directly. Reverting this will restore functionality. A follow up bug will be filed to remove the code generating this report.
unlink feeds as well
remove the tests associated with builds
move crashes per user into the non-overview opt group
fixes bug 1024113 - remove view for builds

Removes the unlinked view for the nightly builds report. This leaves the model and api call intact; it is less clear who is using that and how.
Merge pull request #2109 from lonnen/1021520-unlink

1021520 unlink the builds report