Develop branch: App-specific mfip tool

Two commits:

1. Allow the application to use all 7 remaining bits of the first command byte received via FIP Minor rewriting to avoid while(1) - improve readability.
2. Refactor mfip_urv_lib to allow application-specific callbacks. This means we can have an application specific version of the mfip_urv tool to format data received in a nice way.