[PATCH] Fix util._statfiles_clustered() failing at root of a windows drive

[Andrei Vermel]

> What problem does it solve ?
> 
> ""
> X:\>echo a > a
> 
> X:\>python
> Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 
> 32 bit (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
> >>> from mercurial.util import _statfiles_clustered
> >>> [s.st_size for s in _statfiles_clustered(['x:\\a'])]
> [4L]
> """

Sorry, missed the last bit.

M:\>ls
qqq.txt

M:\>python
ActivePython 2.4.3 Build 12 (ActiveState Software Inc.) based on
Python 2.4.3 (#69, Apr 11 2006, 15:32:42) [MSC v.1310 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from mercurial.util import _statfiles_clustered
>>> [s for s in _statfiles_clustered(['x:\\qqq.txt'])]
[None]