Put back OAuth2 login
example: Move signin/change/signup part into footer
Update readme & changelog
Handle bad-token errors

401 errors now trigger a logout, so a bad token
will generate one error then be removed.
example: Move example into example/vanilla
gulp: init() now returns the config object
gulp: Add defineTasks()

This function allows to be sure the tasks are
defined in the right gulp environment.
example: Add example ‘stylus’