Added general function to flatten array

    .module('kg-app')

    .service('GeneralUtils', [function() {

        return {

            // After: https://stackoverflow.com/questions/10865025/merge-flatten-an-array-of-arrays-in-javascript/39000004#39000004

            flatten: function(arr, result = []){

                for( let i = 0, length = arr.length; i < length; i++ ){

                    const value = arr[i];

                    if( Array.isArray(value) ){

                        this.flatten(value, result);

                    }

                    else{

                        result.push(value);

                    }

                }

                return result;

            },

            removeArrayBfromArrayA: function( arrayA, arrayB, attributeToCheck ){

                for( var i = arrayA.length - 1; i >= 0; i-- ){

                    for( var j = 0; j < arrayB.length; j++ ){