[BUG #7152] picker widget not "stopping" button events 


* Added preventClickEvent method
* prevented click event for button and widgets inside a popup, which are intended to hide the popup. 
[BUG #7152] picker widget not "stopping" button events 


* Added preventClickEvent method
* prevented click event for button and widgets inside a popup, which are intended to hide the popup.
[BUG #7152] picker widget not "stopping" button events 


* Added preventClickEvent method
* prevented click event for button and widgets inside a popup, which are intended to hide the popup.
Fixed minor bug in qx.Mobile list.