report errors when plugins can't be loaded
report errors when plugins can't be loaded

Change-Id: Ib1aa3416b516ae6835c33a482bf8d3c924cf72e6
Reviewed-on: http://codereview.qt.nokia.com/2373
Reviewed-by: Qt Sanity Bot <5581206bb7e0307f0d99eb71898ae6b694149ca5@ovi.com>
Reviewed-by: Lorn Potter <0e329dfd61bdd4e2b2b708a31f12f199a7656feb@nokia.com>

richardmg/qtsensors,mer-qt/qtsensors,richardmg/qtsensors,kobolabs/qtsensors,kobolabs/qtsensors,richardmg/qtsensors,richardmg/qtsensors,mer-qt/qtsensors,kobolabs/qtsensors,richardmg/qtsensors,mer-qt/qtsensors,mer-qt/qtsensors,mer-qt/qtsensors,kobolabs/qtsensors