Create a standalone script to warn changes on dev which do not have latest feature branch as a pick-to target

When a new feature branch is created, it's easy for open changes on dev to be left behind and not be included in the new feature branch if their Pick-to: footers are not manually updated.

A script needs to be created to identify the latest feature branch of a major branch and warn any outstanding changes on dev which have pick-to targets but do not specify the latest release branch. The script should not auto-update the commit message though, since while omission of the new branch is probably an error, the decision is best left up to a human. Instead, the script should -1 any changes with a comment about the probably missing pick target.