Adds controller spec for switching language tree.
Raises the Capybara wait time for language tree switching feature.
Removes the invalid bytechar rescue code, because Rails 4 finally returns BadRequest errors.
[Rails 4] Removes attr_accessible from models.
[Rails 4] Permit all admin resources controllers params as default.

Don't worry, we will pass this through authorization provider later. This is only a temporally solution.
Adds rails 4 todo list
Permits params in admin/contents_controller
Sets permitted params for admin/pages_controller
Sets secure params for admin/users_controller.