Add support for baseline voltage temperature characterization

[vicatcu]

Currently the software codes a single table for all Eggs based on the manufacturer data sheet for the gas sensors. Given a temperature controlled environmental chamber, we can characterize the actual temperature response of each Egg individually. capture that data in the Egg, and use it to improve the accuracy of the Egg's measurements. In order to do this some additional commands will be needed to support manipulating data tables, and then using that information at run-time if it is available. So as not ti adversely affect existing user's who don't have valid characterization data in their Eggs, the software should gracefully fall back to the previous behavior in its absence.

[vicatcu]

Addressed by 2e46ee576ff87ffd90f268e1222e0f0363495fdd