Common: refactoring class mlk::size 1. Make uniform size representation in JSON format: { "width": 100, "height": 200 } The Javascript API was using this form while an array was used in loaders. 2. Create brand new functions in util::json to parse mlk::size objects, Updated util::json::require_(u)int as well. 3. Add new tests for mlk::size object, 4. Get rid of utilities in loader as they are in util::json instead.