Blocked revisions 87217 via svnmerge

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  r87217 | r.david.murray | 2010-12-13 18:51:19 -0500 (Mon, 13 Dec 2010) | 5 lines

  #1078919: make add_header automatically do RFC2231 encoding when needed.

  Also document the use of three-tuples if control of the charset
  and language is desired.
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