* renamed fromQVariant to convertFromQVariant, the "from" methods imply the object is changed (fromJson, fromString ..)
* implemented fromQVariant - changing the object by QVariant
* moved toQVariant into PQ template
* free function setFromQVariant
* added class
* adjusted settings context
* adjusted "global" methods as register metadata
* improved settings utility
* renamed "settingsallclasses" as settings can also be in other namespaces, settingsallclasses now in core