QtIFW

Implement https support, reuse http downloader.

Fixes Task-number: QTIFW-119

Change-Id: If374603834f5dfe9e7b51f41139cd3b78ad21c61
Reviewed-by: Richard J. Moore <rich@kde.org>
Reviewed-by: Niels Weber <niels.2.weber@nokia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>