Cursor blinks in background

[Fred Kiefer]

After adding a NSLog() statement to the _blink method of NSTextView I
noticed that this method get called, while the window of the text view
is no longer active. This can be seen in the GSTest.app when switching
to another test window after editing text in the NSForm test. In this
case the blinking wont be displayed and is just a waste of computer
time.
The reason for this blinking seems to be that the class NSTextView does
not implement resignKeyWindow. This method gets called on the first
responder, when the window looses key window status. But I am not sure,
what an implementation of this method should do. Just switch off the
blinking cursor? Or more?

Cheers Fred