Combined parent and therapist into user - added routes

Combined the "parent" and "therapist" controllers into a unified "users" controller -- `UsersController.php`.

So, the following routes should work now:

- `/users/register`
- `/users/login`
- `/users/logout`
- `/users/:id/:action`
- All the home pages

(I think that `/users/register` and `/users/login` should be combined into just `/users/login`.) I also moved the "match" and "schedule" controllers into base classes that can be accessed from the `UsersController` - they don't really need to be controllers.