Proposed fix for issue #809

This is a proposed fix for issue #809. 

- Tested using `tox` with python-3.4 and python-2.7 on Xubuntu 14.04
- Tested against namespace packages at root of https://github.com/OpenMDAO/OpenMDAO-Framework on Xubuntu 14.04 and Windows 7.
I think this part can move out of this block (otherwise you're doing the same work over and over again).  But it begs the question: can we just do it all the time?  IOW, maybe something like:

```python
if path:
    path = os.path.normcase(os.path.realpath(path))
for module_path in module_paths:
    log.debug("Load tests from module path %s?", module_path)
    log.debug("path: %s os.path.realpath(%s): %s",
              path, module_path, os.path.realpath(module_path))

    module_path = os.path.normcase(module_path)
```