修复两个问题：

1.如果某行禁用_disabled=true,则这行的_checked,无论如何都是false,因为禁用的目的就是不能选择
2.修复某行设置_disabled=true时，全选状态判断有误的bug

test/routers/table.vue

@@ -54,26 +54,29 @@
                         age: 18,
                         address: '北京市朝阳区芍药居',
                         _highlight: true,
-                        _checked: true
+                        _checked: true,
+                        _disabled: false
                     },
                     {
                         name: '张小刚',
                         age: 25,
                         address: '北京市海淀区西二旗',
-                        _checked: true
+                        _checked: false,
+                        _disabled: true
                     },
                     {
                         name: '李小红',
                         age: 30,
                         address: '上海市浦东新区世纪大道',
-                        _checked: false,
+                        _checked: true,
                         _disabled: true
                     },
                     {
                         name: '周小伟',
                         age: 26,
                         address: '深圳市南山区深南大道',
-                        _checked: true
+                        _checked: true,
+                        _disabled: false
                     }
                 ]
             }