Updated qt5 installer structure.

Updated qt5 installer confs to be more modularized, added creator
confs (note, still the 4.8 version of creator).

Change-Id: Icc4ff4dbc4cffe8baeb32e8ba6474baaef46ae2a
Reviewed-by: Simo Fält <simo.falt@digia.com>
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>