Find and switch to a newer stable libuv version.

[hnakamur]

Possibly the newest tag "node-v0.9.1" will do.
https://github.com/joyent/libuv/tree/node-v0.9.1

We need to investigate if it is actually safe to switch.

We need to integrate c-ares with libuv since c-ares was removed from libuv.
See [ANN] c-ares removed · Issue #518 · joyent/libuv

[hnakamur]

I'm working on this at
https://github.com/hnakamur/lev/commits/add_c-ares_submodule/