Handling T* and T& of function parameter

[edimetia3d]

When a function uses T* (or T & ) as a parameter, this function will usually want to modify the object it pointed to, e.g.

ErrorCode GetValue(int * v);
ErrorCode GetValue(std::vector<int> * vec);

However:

1. Python itself does not support mutable int
2. pybind11 will create a copy when T is a std container type, any modification to the copied object will not return to python runtime.

These cases should be handled automatically, or at least a warning should be printed.