GlobalInt

Also modifies `.gitignore` so the repo can exist in the same directory as a testing custom story.

`GlobalInt` is just a precursor, I may turn it into a macro to easily define `LocalInt` as well as the other available types. `Local/GlobalString` will obviously need a good few of the operators removed.

The wrapper supports all operators except the mysterious `>>>` and `>>>=` operators. In addition, assignment of a `GlobalInt` to an `int` or other primitive type does not work.

```
int x;
GlobalInt g("myglobal");
x = g; // will not work
g = x; // works
x = g + 0; // works. opAdd returns an int, not a GlobalInt@ like compound operators do
```