Clean up CMakeLists in all C++ examples

+ Rename output executables to match directory structure
+ Remove libraries for small examples
+ Supress -Wreturn-type warnings for singleton that is intentionally not copyable

cpp/cmake-example/apps/say-hello.cpp

@@ -6,7 +6,7 @@
 ################################################################################
 */
 
-#include <lib-klips.hpp>
+#include <lib-example.hpp>
 #include <iostream>
 
 int main () {