Rename 'release-tools' as 'packaging-tools'

On windows the linker may substitute the 'release' with debug.
First collision and build time error encountered with qtenginio
Windows debug build.

See also: QTBUG-491

Change-Id: I409acfaf78189c9d1cce8dc06474e3772826605b
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>