add util.samestat function for windows. windows does not have os.path.samestat, and stat().st_ino is always zero, so util.samestat always returns false on windows.

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m test -d "1000000 0"
hg history
hg manifest
hg cat a
hg verify