Use of boost::adl_move_swap.

Replaced <algorithm> with <functional> where needed
Added basic equal/lexicographical compare algorithms to avoid complex <algorithm> include and ADL problems in some compilers

example/doc_unordered_set.cpp

@@ -12,7 +12,7 @@
 //[doc_unordered_set_code
 #include <boost/intrusive/unordered_set.hpp>
 #include <vector>
-#include <algorithm>
+#include <functional>
 #include <boost/functional/hash.hpp>
 
 using namespace boost::intrusive;