Upgraded to latest Rust-Empty

Closes https://github.com/PistonDevelopers/rust-dsp/issues/17
Merge pull request #21 from mitchmindtree/master

impl'd Encodable/Decodable for NodeData, changed primitive int types for ...
Merge pull request #18 from bvssvni/master

Upgraded to latest Rust-Empty
Removed unnessary main.rs