Create an independent dependency resolution script.

Calculates dependencies without using Closure Compiler,
to be used with alternate compilers and build tools.

Progress on #7 and #74.
It may be cleaner to make this `reduce`.
```javascript
arrays.flatten = function(arr) {
  if (!util.isArray(arr)) {
    return arr;
  }
  return arr.reduce(function(prev, cur) {
      return prev.concat(arrays.flatten(cur));
  }, []);
};
```

This would allow us to remove `arrays.convert`.