Fix up Debugger helpers to be able to dump QObject's with CDB.
- Make container dumper routines set "childnumchild" when known in order to avoid roundtrips; avoid repeated invocations of container.end(). - Completed dumper information in some places to avoid roundtrips. - Extended QVariant helpers by dumpers for common GUI types (rectangles, points, sizes, fonts, size policies). - Introduced artificial QObjectChildList/QObjectProperty types to be able to dump QObject children and properties without using gdb expressions. - Fixed dumping of Signal/Slot list to pass on correct types. Avoid recursions if signal is connected to self. - Replaced expressions by addresses in the dumpers to it make work for CDB. - Reworked dumper test program to have -a, making it usable for tests, add further types. - Gdb: Clear output buffer before calling dumpers, avoiding mixups in case evaluation of expression fails. - Fix the dumper parser used by CDB, do not be fooled by "<synthetic>" addresses, etc. - Pass on a "dumperVersion" in initial query.