Remain undecided on begin/rescue/end

In #135 this remained a controversial decision, with some arguing that
the code becomes difficult to read without `begin`, others arguing that
it makes it too hard to see what the raising method call is. Since we
are still undecided on this, we can revert this decision.

This reverts commit eb024567d5cb7eed7cfeeac122f133b239d4f3ed.