add chipmunk physics package

How do I know the test ran successfully?

```
$ make chipmunk
[target]   i686-pc-mingw32.static with 1 goal from command line
[build]    chipmunk
[done]     chipmunk
```
Hmm I turned on shared builds but I'm seeing what I'm not supposed to see:

```
./usr/i686-pc-mingw32.static/lib/libchipmunk.a
./usr/i686-pc-mingw32.static/lib/libchipmunk.dll
```

Now I'm trying to find another cmake package to see how they do it.