Why don't you just use `std::to_string`? 
Because it's missing on android/gnustl?
Maybe we should stick with `std::to_string` and add the missing functions to the `std` namespace **only** for android/gnustl builds?

I know .. it's not the best option to mess within `std::` **BUT**:
- it will keep the library clean
- we only have to touch a single spot, if gnustl is updated
- we fix the problem for the user too (otherwise the problem continues within the users game code)