Addition of container directory.
Function fill_set moved to its own header.
Function fill_set made member of bst, so that it is equal to std::set.
It is now possible to specify the size of the transform on the command line.
Fix in wrond use of std::ref.
Addition of more member functions on bst and improvements on its tests.
Meta fuction size_of moved to its own header.
Addition of std::sort in the benchmarks.