automoc: do not handle generated artifacts
automoc: do not handle generated artifacts

We have a chicken/egg problem here with the current design, if we're
allowing automoc to handle generating artifacts.
A code generator must know if its generating mocable cpp/hpp files and
add the moc_cpp / moc_hpp file tags accordingly.

Change-Id: I29c4bfc3d61a0e6430346c0887bf378ea6eb0e97
Reviewed-by: Oswald Buddenhagen <6a8868beda3e139b5ac22b2534a23d3e6ba81819@nokia.com>
Reviewed-by: Joerg Bornemann <47777b9406dbddd02a3fdca8341789a013805a11@nokia.com>

gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,Distrotech/qbs,villytiger/qbs,Distrotech/qbs,villytiger/qbs,gatzka/qt-labs-qbs,Distrotech/qbs,qt-labs/qbs,villytiger/qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,Distrotech/qbs,gatzka/qt-labs-qbs,Distrotech/qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,villytiger/qbs,Distrotech/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,Distrotech/qbs,qtproject/qt-labs-qbs,villytiger/qbs,villytiger/qbs,qtproject/qt-labs-qbs,qt-labs/qbs