Initial phone battery support test

Phone battery level display test build

Probably Android only? No iOS? - definitely not supported in SDK emulator

Does NOT support charging status, only level

pre 3.13 version with Slate

go back to concat JS due to CloudPebble bug

CommonJS-style does NOT work in CloudPebble unless all the JS resources are removed and then added again. For single js code, can switch settings to concat and then back to CommonJS-style.