Merge branch 'sk/force-if-includes'

"git push --force-with-lease[=<ref>]" can easily be misused to lose commits unless the user takes good care of their own "git fetch". A new option "--force-if-includes" attempts to ensure that what is being force-pushed was created after examining the commit at the tip of the remote ref that is about to be force-replaced. * sk/force-if-includes: t, doc: update tests, reference for "--force-if-includes" push: parse and set flag for "--force-if-includes" push: add reflog check for "--force-if-includes"