[PyQt] dense about qvariant and dict

[David Cortesi]

qv.toPyObject() gives the same as qv.toMap, a python dict in which the
keys have been changed to QStrings (these keys were all python strings
originally, don't know what it would do with numeric keys) and the
values to QVariants.

This is ok in the sense that no data is lost, but adds some code in
the setItemValue routine, having to un-Qt every key and value.