Development branch of unordered.

svn path=/branches/unordered/dev/doc/; revision=42731
Merged revisions 42740-43816,43819-43838 via svnmerge from 
https://svn.boost.org/svn/boost/branches/unordered/trunk

svn path=/branches/unordered/dev/Jamfile.v2; revision=43839
Remove the unordered/dev branch as it's now fully merged and no longer serves
any purpose.

svn path=/branches/unordered/dev/doc/; revision=45744