'Convert the path into a form compatible with URLs.
On Unix-like systems, a path looks like foo/bar/baz.png, which is already
compatible with the path part of a URL like
http://myapp.appspot.com/foo/bar/baz.png
But on Windows, a path can also look like foo\bar\baz.png, which will fail
if we naively try to match it against a URL-style pattern like foo/**.png.
So we convert \ into / in that case. On Windows, / is also accepted as
a separator, so it is correct for that inputs foo\bar\baz.png
and foo/bar/baz.png both produce output foo/bar/baz.png.
Args:
path: the path to a file
Returns:
The input path, but using / as separator even if the OS uses \.'

@staticmethod
def _UrlifyPath(path):

    return (path if (os.path.sep == '/') else path.replace(os.path.sep, '/'))
