Initial dev release!

Initial release!

Save and reuse term merge actions with a little gui to delete the actions.

A whole lot of changes. We should be near to the stable release now.
Every release blocker we know of was fixed. We need your final feedback now.

Don't forget to update ERR at the same time to 8.x-1.0-rc7!

A next step towards a stable release.

Most important additions: A diff plugin, a fix to make Search API integration work, and many bugfixes.

Changes since 8.x-1.0-rc6:

Initial dev release.