git module: support windows
git module: support windows

remove dependence on `pipes.quote` in favor of
`subprocess.list2cmdline`, which is cross-platform. This permits the
git module to be used by windows minions.

`list2cmdline` quotes a little differently than `pipes.quote`, but
produces a safe result:

        >>> x = 'A & "B"'
	>>> print pipes.quote(x)
	'A & "B"'
	>>> print subprocess.list2cmdline([x])
	"A & \"B\""

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt