Node 0.11.x support

With these changes, node_mdns builds and runs under Node 0.11.14 and nan 1.3 although I cannot say with certainty as amount of testing it received with these changes is too little.
I'm very much against dependencies.

Both of them are tightly coupled to node. In fact they are part of node but... oh well. Pinning a version does not seem right either. The want the latest round of nan compatibility hacks, no? What do you suggest? `>=`?