Improvemets on the benchmark program and README
Renaming README.
node_pool renamed to node_stack. Some member functions have also been renamed.
Class node_stack taking a node_type instead of node value_type.
First humble use of std::allocator_traits.
Addition of the inner allocator type in the class bst.
Many improvements towards making the class bst use the new C++11 allocator model.
Removal of rtcpp::allocator. Class bst is using std::allocator instead.
Improved documentation on test_bst.
More documentation for the benchmark program.
Improvements in the README file.
Small correction on the README file.
Code that links the stack has been moved into a function.
Internal stack buffer removed from the stack. It is not up to the user to
provide a pointer to the top of the stack.
Further changes in the design of bst.

Now its allocator takes the node_type instead of T.
Improvements in the README file.