Add containers module with initial implementation and integrate into CMake build system.

cpp/classes/IComparable.h

@@ -1,8 +1,13 @@
 #ifndef POINTER_ICOMPARABLE_H
 #define POINTER_ICOMPARABLE_H
+#include <iostream>
 
 class IComparable {
 public:
+    // only for presentation purposes
+    IComparable() { std::cout << "IComparable()" << std::endl; }
+    virtual ~IComparable() { std::cout << "~IComparable()" << std::endl; }
+
     virtual int CompareTo(IComparable* other) = 0;
 };