Added -i/--id option for USB device product ID to be set to uart mode. Removed -p option and prompting about whether the opened device is the correct one. Other cleanup and rearranging.
Added -i/--id option for USB device product ID to be set to uart mode.
Removed -p option and prompting about whether the opened device is
the correct one. Other cleanup and rearranging.

swift-nav/piksi_sample_grabber,swift-nav/piksi_sample_grabber,cbeighley/piksi_sample_grabber,cbeighley/piksi_sample_grabber