Fix crash caused by deleting buffer we do not own

[JosiahWI]

This PR fixes #27 by not deleting the buffer in the render core after we get it from the pipeline.

The documentation in pipeline.h,

    /**    
     * Create a new object that will be managed by the pipeline    
     *    
     * @tparam T type of the object to be created    
     * @tparam Args types of constructor arguments    
     * @param args constructor arguments    
     * @return T* pointer to the newly created object    
     */    
    template<typename T, typename... Args>
    T *createOwned(Args&&... args) {
        return own(std::make_unique<T>(std::forward<Args>(args)...));
    }

and

    /**    
     * Create a new object that will be managed by the pipeline    
     *    
     * @tparam T type of the object to be created    
     * @tparam Args types of constructor arguments    
     * @param args constructor arguments    
     * @return T* pointer to the newly created object    
     */    
    template<typename T, typename... Args>
    T *createOwned(Args&&... args) {
        return own(std::make_unique<T>(std::forward<Args>(args)...));
    }

makes it clear that the pipeline will delete the buffer. We are not supposed to.

To do

Ready for Review.

How to test

Compile and see that ./test_loop.py no longer hangs.