Patch by Brian Hooper, somewhat augmented by GvR, to strip a trailing

Patch by Brian Hooper, somewhat augmented by GvR, to strip a trailing
backslash from the pathname argument to stat() on Windows -- while on
Unix, stat("/bin/") succeeds and does the same thing as stat("/bin"),
on Windows, stat("\\windows\\") fails while stat("\\windows") succeeds.
This modified version of the patch recognizes both / and \.

(This is odd behavior of the MS C library, since
os.listdir("\\windows\\") succeeds!)