QtIFW

Rewrite to use QHash instead of QVector.

Since add and remove are the most common tasks of the class,
and both functions did linear lookups for the package, a hash
should be the better container to use here.

Change-Id: I0ea8cb8683bc106c3b33e3bba7ff4c9af2b7611b
Reviewed-by: Jarek Kobus <jaroslaw.kobus@theqtcompany.com>