Changeset 5d8b0dd in rtems-docs for images

waf: Remove as many sys path hacks as we can.

There are still sys.path hacks in the conf.py files. They cannot
be removed because the instance of python running the sphinx-build
command does not see our top level path hacks. I looked at using
PYTHONPATH but I could not figure out how to set a process environ
var for a waf build instance.