Ignore any files not ending in .qml when adding QML resources

Qt 5.8 includes compiled QML caching, which creates .qmlc files on disk.
These shouldn't be added as actual QML objects. In addition, anything
that does not end in .qml is probably not something that can actually be
parsed as QML, so ignore those too.

cura/CuraApplication.py

@@ -695,6 +695,10 @@ class CuraApplication(QtApplication):
             if type_name in ("Cura", "Actions"):
                 continue
 
+            # Ignore anything that is not a QML file.
+            if not path.endswith(".qml"):
+                continue
+
             qmlRegisterType(QUrl.fromLocalFile(path), "Cura", 1, 0, type_name)
 
     def onSelectionChanged(self):