Implement Boosting Query #625
Boosting instead of BoostingQuery #625
Merge pull request #626 from Yitsushi/625-implement-boosting-query

Implement Boosting Query #625
Merge some of update by document and script

These share many of the same options so it makes sense to merge them.

Closes #628
Closes #627
Rename Updatable to AbstractUpdateAction
Expand on changes.txt