update to nan-1.0.0 for node-11 support

hey dude,

I wanted to use this module in node-0.11 so I took the liberty of updating it to nan-1.0.0. some notes:
1. I use the new NanAsyncWorker class. in order to get parseArgs to work, I feel like I hacked it a bit, but we're working with node-0.10 and node-0.11
2. I simplified the arg parsing with some inline functions. these could be possibly further specialized to include the ranges specified. I might do this in the future, as I kinda want this for another project I'm working on.

cheers!