Updates to meta::scoped_reg_c and event::sub_c.

- scoped_reg_c now has a default functor, reset_scoped_reg_reset_f. It
simply calls the wrapped type's reset() method.
- sub_c renamed its unsub() method to reset().
- Bashed sub_c's dedicated reset_f.
Small doc updates.
Fixed wrapping after automated refactor.
First pass as task affinity module.
First pass at task module.