Reset activeTarget before each overlay test
Merge pull request #1378 from aadsm/overlay-specs

Reset activeTarget before each overlay test
Fix variable scope issues in template-spec
Generate new data-montage-ids using the same base id

When adding new DOM nodes to a template solve the data-montage-id
clashes by generating a new id based on the original id.
Update mousse version to use the labeler API that supports this.