Documentation fixes:

* allocator_traits was not properly placed in namespace boost::container.qbk
* Fixed some typos
* Added "Known Issues" section with move emulation problems.

include/boost/container/allocator_traits.hpp

@@ -38,10 +38,11 @@
 #include <boost/container/detail/preprocessor.hpp>
 #endif
 
-#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
-
 namespace boost {
 namespace container {
+
+#ifndef BOOST_CONTAINER_DOXYGEN_INVOKED
+
 namespace container_detail {
 
 //workaround needed for C++03 compilers with no construct()