QtIFW

Fix dangling resource data.

Task-number: QTIFW-168

Use QByteArray as a data container for resources to keep a reference to that
data till the data is needed / the QByteArray exists.

Change-Id: I2436ae2204bd1bdb834e6c8e434b2673b12c4fad
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>