vmstat - Change re, pi, po and fr from counts to bytes

vmstat - Change re, pi, po and fr from counts to bytes

* Change re, pi, po, and fr to bytes.  re, pi, and po were previously
  paging related transaction counts (not even page counts) which really
  tells us absolutely nothing.

  The values are now displayed in terms of bytes reclaimed, paged in,
  paged out, and freed, with appropriate suffixes (nothing, K, M, or G).