CMakeLists.txt: use option() for build options to play nice with ccmake and cmake GUIs
CMakeLists.txt: use option() for build options to play nice with ccmake and cmake GUIs
SeReRPRo/badvpn,SeReRPRo/badvpn,SeReRPRo/badvpn,SeReRPRo/badvpn,SeReRPRo/badvpn