Merge branch 'jk/detect-push-typo-early'

Catch "git push $there no-such-branch" early.

* jk/detect-push-typo-early:
  push: detect local refspec errors early
  match_explicit_lhs: allow a "verify only" mode
  match_explicit: hoist refspec lhs checks into their own function

diff --cc remote.c
Simple merge