Store Dex TX ID in Flash
Store Dex TX ID in Flash

Adds functions to erase and write the Dexcom TX ID to flash, so it
doesn't have to be reset every time.

jamorham/wixel-sdk,seattlebrighton/wixel-sdk,jamorham/wixel-sdk,jamorham/wixel-sdk,seattlebrighton/wixel-sdk,seattlebrighton/wixel-sdk,jamorham/wixel-sdk,seattlebrighton/wixel-sdk