QtIFW

create headless mode

some build scripts want to generate a update file without launching
any user interface. Introduce some refactoring to be able to use
the networking code from a non-gui application as well

Change-Id: I187b7287095c89e140fbb68d9fdffe42c481ed52
Reviewed-on: http://codereview.qt-project.org/6013
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@nokia.com>