#1628 onChanging stop to fire after onOK

[Jumper Chen]

For example,

<vbox>
<textbox id="tb1"/>
Type here, on changing, C is added above. On OK (enter key), O is added above:
<textbox id="tb2" onOK="tb1.value += 'O';" onChanging="tb1.value += 'C';"/>
</vbox>

[Jumper Chen]

Fixed since Nov. 27.