Very big and ugly memory leaks

[Amiaux Benoit]

After having read CombineTag code, it seems this class is lacking a 
destructor too. So memory will leak when two types of tags are present. 
I'm not able to test this case though.

So again, adding a proper destructor is the solution:

    ~CombinedTag()
    {
        delete tag1;
        delete tag2;
    }