chrome.hid-app: Handle errors in onDataReceived
chrome.hid-app: onDeviceFound may be called with 0 devices
chrome.hid-app: Provide immediate feedback to user when connecting

With current firmware, it takes a few connection attempts to reach connected state. Let the user know that the device has been detected, and is in process of connecting.
Merge pull request #94 from jnwatts/chrome_app_fixes_for_limpkin

Chrome app fixes for limpkin