Merge an unordered documentation change that I missed before.

Merged revisions 54914 via svnmerge from 
https://svn.boost.org/svn/boost/trunk

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  r54914 | danieljames | 2009-07-12 19:03:35 +0100 (Sun, 12 Jul 2009) | 1 line
  
  Add constructors to the methods for controlling bucket size in unordered containers.
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[SVN r55211]

libs/unordered

@@ -1 +1 @@
-Subproject commit 1bc3ae3d9dba1912de9f5120cbbac3fd4f8ee906
+Subproject commit df1dad5cb66ecec06bc4b81c6f3e7f655eeb6c14