Add a simple test for QVariant carrying a QSharedPointer<QObject>

Change-Id: Ibe17355c7ed8d4af7fda6261d72cfd64779471a7
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
QUrl: ensure that setPath("//path") doesn't lead to scheme://path

which would interpret 'path' as a hostname.
The check is in the public setPath so that the internal one can still
support parsing URLs such as ftp://ftp.example.com//path.

[ChangeLog][Important Behavior Changes][QUrl and QUrlQuery]QUrl now
normalizes the path given in setPath, removing ./ and ../ and duplicate
slashes.

Change-Id: I05ccd8a1d813de45e460384239c059418a8e6a08
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>