Debugger: Add a more generic way to distinguish Qt 4 and 5 in dumpers

Change-Id: I1f020032984fb61554b75cc404784d39d9464890
Reviewed-by: hjk <hjk121@nokiamail.com>
Debugger: Make QPixmap dumper work in release builds

Change-Id: Ib50d6968fcac38fa59df5c34c578b4a618dc9e06
Reviewed-by: hjk <hjk121@nokiamail.com>