add --opmode (import|export) option

[mydevpeeps]

adding this option will allow for the same arguments to be used for multiple operations. for example, --config points to a JSON file. This file could be used to either read from to make Configuration.h/Configuration_adv.h .. or it could be used to name a new JSON file to create from an existing Configuration.h/Configuration_adv.h set.

import = reads from JSON file and makes configuration files
export = reads configuration files and makes JSON file.