Implemented the lightning experienced-based planning framework

Also contains https://github.com/ompl/ompl/pull/39

See publication [A Robot Path Planning Framework that Learns from Experience](http://queue.ieor.berkeley.edu/~goldberg/pubs/berenson-ICRA2012-final.pdf)

Part of my GSoC project.
Maybe a member variable of type std::vector<double> would help with the memory allocation. Inside this function you can resize if necessary and initialize each element with one call to std::vector<double>::resize. If the vector is already large enough, then just use std::fill to reset the initial values.