do not pollute the global cmake def space --> add_definitions replaced by target_compile_definitions
QTCSV_LIBRARY is only a private compile define, because it should be used only by the lib itself and no qtcsv consuming target should use the define
an additional public QTCSV_STATIC_LIB define is introduced to make sure that QTCSVSHARED_EXPORT is empty for static lib builds
--> those changes makes it possible to cross-compile from linux to windows with mingw shared and static version
-Wmissing-include-dirs is removed, because it breaks in some conditions my build, the conditions are:
rebuilding the lib statically without tests --> automoc is executed, but produces nothing else then not existing include dir entries --> handling this warning as error, breaks the build
-Wmissing-include-dirs is removed, because it breaks in some conditions my build, the conditions are: rebuilding the lib statically without tests --> automoc is executed, but produces nothing else then not existing include dir entries --> handling this warning as error, breaks the build