diable copy for qgsrendererv2 and derived

it was buggy (crash) an certainly not used (because of crash)

The bugs all have the same pattern:

class A
{
public:
  A()
    : mPtrToResource(new Resource)
  {}
  ~A()
  {
    delete mPtrToResource;
  }
private:
  Resource * mPtrToResource;
};

If you happen to make a copy of A, intensionnally or otherwize (c++ is eager to make copies), you have a double delete on the resource.