BlMouseDownEvent subclasses should have a #sendTo:

[plantec]

Since we have subclasses, it is desirable to have #sentTo: to simplify event handler implementation.
Currently, the modifiers has to be checked in handlers whereas it has already been checked in the mouse processor.

Having a #sentTo: implies updating existing handlers.
I've counted 3 that should be revised.
They are all a subclass of BlEventListener

[plantec]

BlMouseDownEvent >> #ifPrimary: aPrimBlock secondary: aSecBlock middle: aMidBlock other: anotherBlock
is crappy and would be not necessary