Merge remote-tracking branch 'origin/master'

Merge remote-tracking branch 'origin/master'

* origin/master: (22 commits)
  tests: add metadata-bad-mdaheader.sh
  tests: add metadata-bad-text.sh
  tests: add outdated-pv.sh
  tests: add metadata-old.sh
  tests: add missing-pv missing-pv-unused
  metadata.c: removed unused code
  improve reading and repairing vg metadata
  add a warning message when updating old metadata
  vgcfgbackup add error messages
  vgck --updatemetadata is a new command
  move pv header repairs to vg_write
  process_each_pv handle outdated pvs
  move wipe_outdated_pvs to vg_write
  create separate lvmcache update functions for read and write
  fix vg_commit return value
  change args for text label read function
  add mda arg to add_mda
  keep track of which mdas have old metadata in lvmcache
  ability to keep track of outdated pvs in lvmcache
  ability to keep track of bad mdas in lvmcache
  ...