Tests fail on OS X

The tests `shared-test-core` and `embedded-test-core` are throwing the following errors on OS X:

```
/Users/jzachary/redjack/osx/libcork/tests/test-core.c:513:E:net-addresses:test_ipv6_address:0: (after this point) Received signal 6 (Abort trap: 6)
/Users/jzachary/redjack/osx/libcork/tests/test-core.c:571:E:net-addresses:test_ip_address:0: (after this point) Received signal 6 (Abort trap: 6)
```