[tree] Fix some documentation typos. Add explanation of date to vnum decomposition.

git-svn-id: http://svn.boost.org/svn/boost/sandbox/predef@76967 b8fc166d-592f-0410-95f2-cb63ce0dd405

libs/predef/doc/html/index.html

@@ -59,7 +59,7 @@
 </table></div>
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
-<td align="left"><p><small>Last revised: December 15, 2011 at 03:47:03 GMT</small></p></td>
+<td align="left"><p><small>Last revised: February 10, 2012 at 14:55:42 GMT</small></p></td>
 <td align="right"><div class="copyright-footer"></div></td>
 </tr></table>
 <hr>