Fix API change of node >= 0.9.4

I added status parameters at all uv_after_cb functions for make 0.10 happier, but it makes 0.8 build fails.

I think there could be some ways for fixing this...

1) set package.json node version requirement to >= 0.9.4 or 0.10.x and guide 0.8 users to use older version of node_gitteh.
2) instead of adding parameter, use static cast(which was guided in [wiki](https://github.com/joyent/node/wiki/Api-changes-between-v0.8-and-v0.10), but I think it's bad)
3) use hell of MACROs?