* Use helper functions in staticfiles to redirect.
Previously the browse package invoked staticfiles.Redirect when
redirecting clients who requested a directory but with a Request-URI
that did not contain a trailing '/'. staticfiles.Redirect only used a
relative URI. This change defers the decision of how to format the
Location header value to the helper methods in the staticfiles package.
* Update const URLPathCtxKey in browse package.
36d2027493