Merge branch 'lo'

* lo:
  mount: small change to mount.8 loopdev section
  libmount: one iteration to detect overlap and reuse loopdev
  lib/loopdev: cleanup sizelimit check
  mount.8: Update loop device documentation
  tests: Add loop-overlay test
  libmout: Reuse loop device safely
  Implement loopcxt_check_conflict()
  Add sizelimit to internal API
  mount: Handle MNT_ERR_LOOPOVERLAP
  libmount: Introduce new error: MNT_ERR_LOOPOVERLAP
  libmount: Fix possible crash in mnt_context_setup_loopdev()