Fixes Issue 3508 Clicking on a CheckBox's label triggers two click events

CheckBoxes were sending two click events when their labels were clicked, due to
trickery going on to send ValueChangeEvents only when appropriate.

I've moved all the trickery down to RadioButton, the only place it is actually
needed, and filter out click events on the label. 

Testing: CheckBoxTest has been extended for the specific problem, and I've
manually tested keyboard and mouse interaction with both CheckBox and
RadioButton on Safari, FF3, IE and Chrome. Full suite run against IE7.



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5333 8db76d5a-ed1c-0410-87a9-c151d255dfc7
3 files changed