Blocked revisions 77691,77698,77713-77714 via svnmerge

........
  r77691 | mark.dickinson | 2010-01-22 16:18:09 +0000 (Fri, 22 Jan 2010) | 1 line

  Correct typo in comment.
........
  r77698 | mark.dickinson | 2010-01-22 17:04:07 +0000 (Fri, 22 Jan 2010) | 3 lines

  Issue #7743:  Fix a potential incorrect rounding bug in dtoa.c (2nd bug
  in issue 7743).
........
  r77713 | mark.dickinson | 2010-01-23 20:48:56 +0000 (Sat, 23 Jan 2010) | 3 lines

  Issue #7743:  Add checks for zero inputs to the lshift and mult functions;
  this fixes the first bug described in issue #7743.
........
  r77714 | mark.dickinson | 2010-01-23 21:25:53 +0000 (Sat, 23 Jan 2010) | 1 line

  dtoa.c fix from upstream that fixes incorrectly rounded results for certain subnormals that are also halfway cases.
........