Add `Lang.isRegExp()` method
Add support for `route({})` to Router for routing fully-processed routes

This adds support to Router to accept fully-processed route objects.
This is useful when passing one route's routes to another router, and
for accepting route config objects generated by the server and applying
them to a Y.Router instance on the client.

Closes #1067
Append callbacks specified as arguments to `route.callbacks` in route()

This makes sure to append any var-args callback functions passed to
Router's `route()` method to a route config object's `route.callbacks`.
Only flatten route callbacks arrays once
Give `Lang.isRegExp()` a more descriptive argument name
Add tests for Router supporting fully-processed route config objects
Merge branch 'router-config-objs' into dev-3.x
Add API docs for route objects support in Router
Update Router's user guide for route objects
Update Router's HISTORY for route objects
Build Router
Build YUI