Add picture-card demo

components/upload/demo/picture-card.md

+# 图片卡片样式
+
+- order: 8
+
+上传文件为图片，可展示本地缩略图。
+
+---
+
+````jsx
+import { Upload, Icon } from 'antd';
+
+const props = {
+  action: '/upload.do',
+  listType: 'picture-card',
+  defaultFileList: [{
+    uid: -1,
+    name: 'xxx.png',
+    status: 'done',
+    url: 'https://os.alipayobjects.com/rmsportal/NDbkJhpzmLxtPhB.png',
+    thumbUrl: 'https://os.alipayobjects.com/rmsportal/NDbkJhpzmLxtPhB.png',
+  }]
+};
+
+ReactDOM.render(
+<div className="clearfix">
+  <div style={{float: 'left'}}>
+    <Upload {...props}>
+      <div className="upload-trigger">
+        <Icon type="plus" />
+        <div className="upload-trigger-text">上传照片</div>
+      </div>
+    </Upload>
+  </div>
+  <a href="https://os.alipayobjects.com/rmsportal/NDbkJhpzmLxtPhB.png" target="_blank" className="upload-example">
+    <img src="https://os.alipayobjects.com/rmsportal/NDbkJhpzmLxtPhB.png"/>
+    <span>示例</span>
+  </a>
+</div>
+, mountNode);
+````
+
+````css
+/* 配合样式可以做出上传按钮和示例效果 */
+.upload-trigger {
+  width: 96px;
+  height: 96px;
+  padding: 24px 0;
+  border: 1px dashed #d9d9d9;
+  border-radius: 6px;
+  background-color: #fbfbfb;
+  text-align: center;
+  cursor: pointer;
+}
+
+.upload-trigger i {
+  font-size: 28px;
+  color: #999;
+}
+
+.upload-trigger-text {
+  margin-top: 8px;
+  font-size: 12px;
+  color: #666;
+}
+
+.upload-example {
+  position: relative;
+  display: inline-block;
+  height: 96px;
+  width: 96px;
+  margin-left: 8px;
+  padding: 8px;
+  border: 1px solid #d9d9d9;
+  border-radius: 6px;
+}
+
+.upload-example img {
+  height: 78px;
+  width: 78px;
+}
+
+.upload-example:before {
+  position: absolute;
+  bottom: 8px;
+  left: 8px;
+  content: ' ';
+  width: 78px;
+  height: 24px;
+  background-color: #808080;
+  opacity: .8;
+}
+
+.upload-example span {
+  position: absolute;
+  bottom: 8px;
+  left: 8px;
+  width: 78px;
+  height: 24px;
+  color: #fff;
+  line-height: 24px;
+  text-align: center;
+}
+````

style/components/upload.less

@@ -7,6 +7,7 @@
   > span {
     display: block;
     width: 100%;
+    outline: none;
   }
 
   input[type="file"] {