Cmake build: Simplify use of qt5 modules

Cmake build: Simplify use of qt5 modules

According to this page:
	http://doc.qt.io/qt-5/cmake-manual.html
the way to replace use of qt5_use_modules() for module "_mod" and target "_target"
is to use
	1.) cmake_minimum_required(VERSION 3.1.0)
	2.) find_package(Qt5${_mod} CONFIG REQUIRED)
	3.) target_link_libraries(${_target} Qt5::${_mod})
The last one sets all reguired libraries, compile flags and needed includes for the ${_target}