qmlplugindump: Fix --path usage with drive letters on Windows.
qmlplugindump: Fix --path usage with drive letters on Windows.

Since we can't import by such a path, we instead use a "." import
and set the uri of the component to the correct path.

Mirrors a change to qmldump in
qt-creator/0c8b4e38fab1862e3427aac7e7db68623bc7f174

Reviewed-by: Thomas Hartmann

corngood/qtdeclarative,jfaust/qtdeclarative,mgrunditz/qtdeclarative-2d,jfaust/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,jfaust/qtdeclarative,qmlc/qtdeclarative,corngood/qtdeclarative,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,corngood/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,jfaust/qtdeclarative,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative,crobertd/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,jfaust/qtdeclarative,corngood/qtdeclarative,corngood/qtdeclarative,jfaust/qtdeclarative,crobertd/qtdeclarative,matthewvogt/qtdeclarative,corngood/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,corngood/qtdeclarative,matthewvogt/qtdeclarative,crobertd/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,crobertd/qtdeclarative,jfaust/qtdeclarative,matthewvogt/qtdeclarative,crobertd/qtdeclarative,qmlc/qtdeclarative