Adding Python Documentation

As this project includes C++ doxygen documentation, but only
some python documentation I have created python documentation
using Epydoc. I know generated code should not go into a
repository, but I wanted to share this with @amdshameer.
Not all methods or attributes are named identically in the
C++ and Python APIs, and not all C++ API components have python
bindings.

Generated the documentation using the following command for completeness:

    $ epydoc -o=./ompl-python-documentation --graph=all --inheritance=included
    /Path/To/Python/Lib/ompl/