MFC r256690:

MFC r256690:
  Add an automatic resize support to the GEOM_PART class.

  When parent provider has been resized, the scheme specific G_PART_RESIZE
  method does an update of scheme's metadata. But all changes are not saved
  to disk, until `gpart commit` will be called.

MFC r265336:
  Add an advice what to do when partition was automatically resized.