Separate out blink(1) commands into blink1.js.

Create a separate Javascript class that represents a particular blink(1)
device and encapsulates the usage of the chrome.hid API.
Feature reports aren't events. They are generated on demand by the device. The way the blink(1) firmware is written the data returned by a GET_REPORT(Feature) request is whatever was generated by the last command executed. I've been considering adding code to throttle this library so that a new command cannot be sent before the result of the previous command has been read.