Remove unnecessary catch-clauses for try-finally

Talked with @spicyj in the chat yesterday when he was trying to reproduce the idea that IE8 doesn't support `try {} finally {}` without `catch(e) {}`. He couldn't reproduce it and I can't either, no matter the craziness.

After searching more I'm 99% convinced that this is actually false. The reason people incorrectly assume this is the case is because IE8 always reports uncaught exceptions at last `finally`. So if you confuse IE8 really well and get a `This command is not supported`, it will report that error and that error alone at the last `finally` clause. Thus leading everyone to believe `finally` is the cause and not the error itself.

This seems to be corroborated here: https://github.com/knockout/knockout/pull/545#issuecomment-10762998

So unless you guys know for sure that this is an issue, I say we get rid of them (because some browsers actually mess up the exceptions when you re-throw them).

Credit goes to @spicyj for bringing it up.