A number of non-reproducible bugs look like they may be due to bad
	event objects. I was assuming that callers retained the events until
	the functions handling them returned, but that assumption may be wrong.
	So I'm retaining/releasing the current event. This is correct in any case.
	I'm also adding a new assertion, but since assertions are in Development
	builds only that is very low risk.

        * kwq/KWQKHTMLPart.mm:
        (KWQKHTMLPart::keyEvent): Add retain/release and a new assertion.
        (KWQKHTMLPart::mouseDown): Ditto.
        (KWQKHTMLPart::mouseDragged): Ditto.
        (KWQKHTMLPart::mouseUp): Ditto.
        (KWQKHTMLPart::mouseMoved): Ditto.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@3142 268f45cc-cd09-0410-ab3c-d52691b4dbfc