function createCategoryModel(dimensionInd, categoryInd, categoryValue, categoryLabel) {
    return {
        dimensionInd: dimensionInd,
        categoryInd: categoryInd,
        categoryValue: categoryValue,
        displayInd: categoryInd,
        categoryLabel: categoryLabel,
        valueInds: [],
        count: 0,
        dragY: null
    };
}
Create and return a new CategoryModel object
@param {Number} dimensionInd
@param {Number} categoryInd
 The display index of this category (where 0 is the topmost category)
@param {String} categoryValue
@param {String} categoryLabel
@return {CategoryModel}