relax check on version of used projects
By default, the version string of a used project (entries in the USE clause of the gaudi_project
function)
are ignored, to simplify the development.
The strict check can be enabled (e.g. in release builds) setting the CMake option GAUDI_STRICT_VERSION_CHECK
to true.
As a by product, I also added some CMake utility functions to manipulate lists.
Fixes GAUDI-1267.