Revert "Revert "don't fetch build when creating profile""

This reverts commit 08385ed9bd2fd82e5414877bc1eea6f80ebd621c.
fix build_spec.minor_release to return tuple of ints
rename numfirst to maybe_add_index
clean up builds.models
make detail migration work with previously migrated and reverted apps
Merge pull request #1807 from dimagi/fix-minor-release

Hotfix minor_release and detail migration issues