Standard compliant std::realloc

[BikingGlobetrotter]

Hi, I am Michael and I am using wrenbind17 (thanks for providing it).
This is my first contribution to make it an even better library (others may follow ;-) ):

I noticed that std::realloc is called inside reallocateFn even if the size is 0.
According to C++ standard ( https://en.cppreference.com/w/cpp/memory/c/realloc ),
the behavior in that case in implementation defined and its usage is discouraged.
Instead it is recommend to call std::free instead (which is also the default implementation inside wren).

Please find my merge request that improves the code in this regard.
Best regards
Michael

[matusnovak]

Hi Michael. Thank you for your contribution!

I have enabled GitHub actions. Linux x64 build failed for unrelated reasons, don't worry about it.

Merging.

[matusnovak]

I have created a new tag: https://github.com/matusnovak/wrenbind17/releases/tag/v1.3.1