Ivar layout change

[Fred Kiefer]

I just moved a bunch of ivars from NSResponder to NSView. They never
should have been there in the first place, but now this is a big change,
as it requires that you recompile all of GNUstep and all your
applications. And don't forget to kill your gpbs daemon, I did :-)

Now more ivar optimisation inside of NSView is possible, but I will
delay this step until I am sure, which of the ivars for NSView will remain.

Sorry for the inconvenience.

Cheers,
Fred