Banged examples first, description changed a little

Dear Michael,

This is the change I hope you have in mind. I kept the supervise examples in below the banged versions. Tell my what you think (I tested all new ! examples!).

Additionally I did not put another issue in this pull request
(but I 'fixed' it in the banged example). To me the 
"Try/Catch/Finally Semantics" should have the `divider` function 
(instead of `add-one`) and catch the `ArithmeticException` instead 
of a `NullPointerException` (because the latter will never show up if you add). 
Do you agree?

Thanks again for all these nice ideas.

Best Regards from Berlin
Stefan Edlich