Apologies for raising this as an issue, rather than suggesting a PR, but I am not a C++ developer, so this could be my misconfiguration as much as anything. However, after following the instructions (including setting up libusb), I was getting errors stating that string was not part of std.
With a quick search, I added #include <string> to AntStick.h and everything compiled.
Great work by the way. Any desires to evolve this project further? I am going to attempt something myself, but if you would like to collaborate, that would be great.