Fixed a few small typos for handling node as well as a
small conditional for building PYTHON.

    * Fixed some NODE_EXECUTABLE->NODEJS_EXECUTABLE instances
    which must have been missed from a previous commit.

    * Added a qualifier for python documentation so both
    BUILDSWIGPYTHON AND BUILDSWIG must be set to add
    dependencies for pydoc.

Signed-off-by: Noel Eck <noel.eck@intel.com>