[popup docs] Update "popupbeforeopen" to "popupbeforeposition" in the events docs
[popup docs] Update "popupbeforeopen" to "popupbeforeposition" in the events docs

startxfr/jquery-mobile,hinaloe/jqm-demo-ja,startxfr/jquery-mobile,arschmitz/uglymongrel-jquery-mobile,arschmitz/jquery-mobile,arschmitz/jquery-mobile,npmcomponent/cbou-jquery-mobile,arschmitz/uglymongrel-jquery-mobile,npmcomponent/cbou-jquery-mobile,arschmitz/uglymongrel-jquery-mobile,hinaloe/jqm-demo-ja,arschmitz/jquery-mobile,npmcomponent/cbou-jquery-mobile,hinaloe/jqm-demo-ja,startxfr/jquery-mobile