QtIFW

Fix missing wizard icon on a windows static build.

Q_IMPORT_PLUGIN() macros are needed in application code
only for Qt4, in Qt5 those are automatically generated by qmake.

Change-Id: Ic75795be402592a0595bb3aa084d0b7ee9a9f8c5
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Karsten Heimrich <karsten.heimrich@digia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>