Expressed offline-mode API in a nicer way.

This allows me to drop the guard ampersands and it explains itself. I don't
know why I bothered with the comments but there you go.
Simplified and formatted offline google.maps.event.

Members with that ugly long argument list are written in three lines whereas
simple members are written in one line. Also it makes more sense to have an
initialized handler and that clearListeners actually does something.
Sometimes the minimalst minimal isn't the best option.
Formatted some initialization as on top of the script.
Replaced empty lines with witty commentary.

Because I hate empty lines!!