Submodule properties should be accessible with "module.submodule" syntax

Currently, in order to access a property in a submodule it is necessary to name the Depends block with an id, and use that to refer to the submodule:

Depends { id:qtcore; name: "qt.core"}
property var v: qtcore.version

It would be nice if it were possible to refer to it as "qt.core" without needing the id. Ie:

Depends { name: "qt.core"}
property var v: qt.core.version

Discussed on the list here: http://lists.qt-project.org/pipermail/qbs/2012-March/000090.html