Power adjustments for laser

[rpegg]

A response to a materials auto calibration question on Oct 4th:

@dan

Unfortunately, there’s a reason that comment was only in the “back in time” segment and not in our crowdfunding campaign or anywhere else. We worked on the feature and could not get it to work well. We ultimately scrapped the plan and went with the direction we’ll be shipping: precalibrated materials with embedded barcodes for “it just works”, and the ability to test and save material profiles for your own favorite materials.