Set DEFAULT in Makefile to 'lib'
Upgrade to latest Rust-Empty
Merge pull request #26 from mitchmindtree/master

Removed old unused commented code from lib and port_audio_back_end
Merge pull request #25 from bvssvni/master

Upgrade to latest Rust-Empty
Merge branch 'master' of https://github.com/PistonDevelopers/rust-dsp
Added macros to simplify implementation of Node trait methods.