hatpconsole was missing libgvc that can be found in graphviz.
Modify the Makefile to add the dependency, and add the file to
find the libgvc (from graphviz). If a project needs libgvc it
should use the file mk/sysdep/libgraphviz.mk instead of the
mk/sysdep/graphviz.mk in order to get the libraries.
As this was a minor change, update the PKGREVISION.

- Detect external dependencies in RobotPkg (sphinx, pyopenl).
- Package external dependency python-simpleparse.
- Teach RobotPkg how to install setuptools based packages
  (rules are duplicated for now in python-simpleparse and
   robot-viewer packages).