QtIFW

Try to read installed packages only in non installer mode.

Change-Id: I955bf5d3b1c543a5f66c8afbb55b1e430d2c4993
Reviewed-on: http://codereview.qt.nokia.com/3588
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>