Implement and_wrap_original

This probably needs more specs and needs features but this converts `and_call_original` into `and_wrap_original` then uses `and_wrap_original` to implement the old `and_call_original` (thus nicely proving it works!).

Closes #650.
These sentences are confusing and inaccurate.  It doesn't make it respond as it normally does...it makes it respond with whatever your block does (but your block has easy access to the original method).  You use `and_wrap_original` (over `and_call_original`) specifically because you want to interfere with how it responds.