Enable possibility to pass an empty prefix
 * This feature can be use to match sub route than delegate unmatched
   paths to a "global" router. The main router would then only contains
   sub router definitions.
 * I would use this in a project like this:

    // Main router definition
    routes: {
      "projects*subroute" : "routeProjects",

      "*subroute" : "routeHome",
    },

    // When needed
    new HomeRouter("");

   If route does not start with "projects", fallback to home
   router which.
Merge pull request #34 from maoueh/feature-empty-prefix

Enable possibility to pass an empty prefix