Doc: Clarified members of QtQml.Models submodule.

Doc: Clarified members of QtQml.Models submodule.

-Took out  members of QtQml.Models submodule from Qt QML and Qt Quick.
-Set up qdocconf files to include QtQml.Models to be part of Qt QML
 doc build.
-Edited the sentences to make it clearer that list and model types
 are in QtQml.Models.
-Placed the Visual* types back to QtQuick 2 module.

-This patch removes several collision pages.

Change-Id: I16e7045162af6852e5d6c3162b6f4cf97a42402b
Reviewed-by: Alan Alpert <aalpert@blackberry.com>