API changed: Native Node.js util.inspect for json formatting and highlighting, chalk dependency removed

Changes:

• Setting logAsJson replaced with type = pretty | json ('pretty' is default)
• chalk dependency removed (hexadecimal colors are no longer supported)
• Color settings based on Node.js utils.ispect.colors
• Error object displays additional details and exposes nativeError
• When typeis set to json, hide nativeError and expose stringified version as errorString