ModUtils.appendAll fix duplicate values
ModUtils.appendAll fix duplicate values

This function supports arrays and single values now.

Change-Id: Ia4d5cf3ef536965a873c067852446f8d4bcc3ad6
Reviewed-by: Marco Bubke <5254e489b34ec8bbce36789100e3fc0f41fa62ef@nokia.com>

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