Merge branch 'jk/push-progress'

"git push" and "git clone" learned to give better progress meters to the end user who is waiting on the terminal. * jk/push-progress: receive-pack: send keepalives during quiet periods receive-pack: turn on connectivity progress receive-pack: relay connectivity errors to sideband receive-pack: turn on index-pack resolving progress index-pack: add flag for showing delta-resolution progress clone: use a real progress meter for connectivity check check_connected: add progress flag check_connected: relay errors to alternate descriptor check_everything_connected: use a struct with named options check_everything_connected: convert to argv_array rev-list: add optional progress reporting check_everything_connected: always pass --quiet to rev-list