Simplify WithReauth() and its dependency workflow.
This change also threads the desired AccessProvider to the reauth
handler, so the reauth handler doesn't have to fish it out through some
hard to maintain back-channel.
diff --git a/context.go b/context.go
index 86f4ef5..2c70ba5 100644
--- a/context.go
+++ b/context.go
@@ -14,7 +14,7 @@
// ReauthHandlerFunc functions are responsible for somehow performing the task of
// reauthentication.
-type ReauthHandlerFunc func() error
+type ReauthHandlerFunc func(AccessProvider) error
// Context structures encapsulate Gophercloud-global state in a manner which
// facilitates easier unit testing. As a user of this SDK, you'll never