Without this fix, generating documentation results in:

```
Traceback (most recent call last):
  File "hacking/module_formatter.py", line 376, in <module>
    main()
  File "hacking/module_formatter.py", line 365, in main
    text = template.render(doc)
  File "/usr/lib64/python2.6/site-packages/jinja2/environment.py", line 669, in render
    return self.environment.handle_exception(exc_info, True)
  File "hacking/templates/man.j2", line 20, in top-level template code
    {% for desc in v.description %}@{ desc | jpfunc }@{% endfor %}
  File "hacking/module_formatter.py", line 94, in man_ify
    t = _ITALIC.sub(r'\\fI' + r"\1" + r"\\fR", text)
TypeError: expected string or buffer
```