Blocked revisions 68941-68942 via svnmerge

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  r68941 | raymond.hettinger | 2009-01-25 15:04:14 -0600 (Sun, 25 Jan 2009) | 1 line

  Promote compress() from a recipe to being a regular itertool.
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  r68942 | raymond.hettinger | 2009-01-25 15:31:47 -0600 (Sun, 25 Jan 2009) | 1 line

  Improved itertools recipe for generating powerset().
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