QmlDesigner: crash fix

qmlSource() contains the source and not qml().

Change-Id: I00d34ca511eb0e1af032a6a9766b3cd8296101f9
Reviewed-by: Marco Bubke <marco.bubke@digia.com>
QmlDesigner.MetaInfo: rename qml() to qmlPath()

qml() is too ambiguous.

Change-Id: I7b56f53f64ce349657e3a462769c11880a1afe04
Reviewed-by: Marco Bubke <marco.bubke@digia.com>