Merge branch 'ps/revision-cmdline-stdin-not'

"git rev-list --stdin" learned to take non-revisions (like "--not") recently from the standard input, but the way such a "--not" was handled was quite confusing, which has been rethought. This is potentially a change that breaks backward compatibility. * ps/revision-cmdline-stdin-not: revision: make pseudo-opt flags read via stdin behave consistently