[BUG #8509] use the new property system in the mobile showcase
[BUG #8509] replaced destroy with enhanced dispose
[BUG #8509] converted to new property system
[BUG #8509] converted to new property system
[BUG #8509] converted to new property system
[BUG #8509] call base class dispose first
[BUG #8509] converted to new property system
minor