Merged revisions 78559,78561-78562 via svnmerge from

Merged revisions 78559,78561-78562 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r78559 | andrew.kuchling | 2010-03-01 20:45:21 +0100 (Mo, 01 Mär 2010) | 1 line

  #7637: update discussion of minidom.unlink() and garbage collection
........
  r78561 | andrew.kuchling | 2010-03-01 20:51:43 +0100 (Mo, 01 Mär 2010) | 1 line

  #7191: describe more details of wbits parameter
........
  r78562 | andrew.kuchling | 2010-03-01 21:11:57 +0100 (Mo, 01 Mär 2010) | 1 line

  #7637: avoid repeated-concatenation antipattern in example
........