Library DoA on Linux

Using `node-libuuid` on linux (ubuntu, at least) results in runtime unresolved symbols. This just hacks up the `binding.gyp` to special case SunOS, Linux and Darwin.  I'm not sure what to do with Win32, but I'm not sure what the state of `libuuid` is there anyway.

Also, your tests when used where this gets installed globally pick up the wrong one, so I changed the test script to pull in the .so, and added `npm test` support.