Merge pull request #2 from bvssvni/master

Added Rust-Empty
added rust-empty makefile, added Goals to README, initialised src and bin
added rust-empty makefile, added Goals to README, initialised src and bin
Merge branch 'master' of https://github.com/mitchmindtree/rust-dsp

Conflicts:
	Makefile
Merge pull request #3 from mitchmindtree/master

Added rust-empty makefile, added Goals to README, initialised src and bin
Added soundstream, created dsp crate, added a test to examples
Added DSP `Node` struct and associated `IsNode` trait.
Fixed docs
Merge pull request #5 from mitchmindtree/master

PortAudio, SoundStream, DSP Node
Added frequency, pitch, waveform, signal and math modules. About a third through Oscillator mod
Added Frequency struct, HasFrequency trait and frequency related calculator functions.
Updated with new modules
fixed docs
Added Oscillator struct, not yet complete
Add Pitch struct, HasPitch trait and associated calculator functions.
Added Signal struct, a helper struct for generating basic signals
Started the Waveform module
Merge pull request #11 from mitchmindtree/master

Frequency, Pitch, Signal, Waveform(WIP), Oscillator(WIP)
Added Envelope and Point structs for amplitude and frequency interpolation.
Added envelope module.