[BUG #8514] use key event normalization
[BUG #8514] fixed tests
[BUG #8514] added disconnectFromWidget method to the layouts
[BUG #8514] added disconnectChild method
[BUG #8514] use overflow:auto for native scrolling
[BUG #8514] removed a test that depends on CSS
[BUG #8514] minor fix