Returns comma-separated preference value as array of values
@param {String} name
@returns {Array} Returns <code>undefined</code> if preference is
not defined, <code>null</code> if string cannot be converted to array
function(name) {
			var val = this.get(name);
			if (_.isUndefined(val) || val === null || val === '')  {
				return null;
			}

			val = _.map(val.split(','), require('utils').trim);
			if (!val.length) {
				return null;
			}
			
			return val;
		}