MFC r209362, r210933, r228356:

r209362 (brian) [1]:

• Add a -t switch for masking output that's above or below certain thresholds. This switch makes it a lot easier to locate problem areas when a process is threatening to consume all of your disk space.

r210933 (joel):

• Fix typos and spelling mistakes.

r228356 [2]:

• Update du(1):
  • Sort arguments alphabetically where appropriate
  • '-B blocksize' is not mutually exclusive of '-h|-k|-m'
  • Mention '-t' in synopsis
  • Other wording improvements
  • Update usage() output to reflect the new synopsis
  • Other miscellaneous improvements

Approved by: brian [1]
PR: 162438 [2]