fix some className issues

components/form/Form.jsx

@@ -11,9 +11,9 @@ class Form extends React.Component {
   render() {
     const { prefixCls, className } = this.props;
     const formClassName = classNames({
-      [className]: !!className,
       [`${prefixCls}-horizontal`]: this.props.horizontal,
       [`${prefixCls}-inline`]: this.props.inline,
+      [className]: !!className,
     });
 
     return (

components/input-number/index.jsx

@@ -12,8 +12,8 @@ export default React.createClass({
   render() {
     const { className, size, ...other } = this.props;
     const inputNumberClass = classNames({
-      'ant-input-number-lg': size === 'large',
-      'ant-input-number-sm': size === 'small',
+      [`${this.props.prefixCls}-lg`]: size === 'large',
+      [`${this.props.prefixCls}-sm`]: size === 'small',
       [className]: !!className,
     });