Rudy/win disk checks

Fixes issue #1008 

Also include a small change in setup.py because we don't bundle httplib2 in this repo anymore.
Built it with the buils-agent-win32 job and installed it on a VM to verify it works.
nitpick but it would be more concise with:
```python
def should_ignore_disk(name, blacklist_re):
    # blacklist_re is a compiled regex, compilation done at config loading time
    if name =='_total' or blacklist_re is not None and blacklist_re.match(name):
        return True
    return False
```