Add CHANGES.md
Make DallasTemperature dependency optional, opt-in
Prettify generated code

Remove unneeded host section, we now use JavaScript to set that up.
Add newlines after every command in the graph.
Add "make release" target, builds an Arduino library ZIP

Can be imported directly into the Arduino IDE
 Sketch -> Import Library... -> Add Library... -> choose .zip
 File -> Examples -> microflo -> Standalone -> build & upload