grunt-usemin与cssmin、uglify结合出现的问题

1. usemin生成的link没有 "/"的结束符，如何配置？

2.我在HTML页面配置 <!-- build:css ${tg.url('css/build.css')} -->，一运行usemin控制台就显示执行了cssmain:generated然后生成了一个叫${tg.url('css的文件夹，，但是我的config里没有这个任务，如果把HTML页面的<!-- build:css ${tg.url('css/build.css')} -->去掉就不会生成。同样，uglify也执行generated，但没生成文件夹

gruntfile.js：

usemin: {
    html: ['dist/templates/*.html']
},
cssmin: {
    css: {
        files: {
            'dist/public/css/build.css': [
                'dist/public/css/build.css'
            ]
        }
    }
},
uglify: {
    js: {
        expand: true,
        //相对路径
        cwd: 'dist/public/js',
        src: '*.js',
        dest: 'dist/public/js/'
    }
}

package.json

"dependencies": {
    "grunt": "^0.4.5",
    "grunt-contrib-concat": "^0.5.1",
    "grunt-contrib-clean": "^0.6.0",
    "grunt-contrib-copy": "^0.8.1",
    "grunt-contrib-cssmin": "^0.13.0",
    "grunt-contrib-connect": "^0.11.2",
    "grunt-contrib-htmlmin": "^0.4.0",
    "grunt-contrib-imagemin": "^0.9.4",
    "grunt-contrib-jshint": "^0.11.3",
    "grunt-contrib-uglify": "^0.9.2",
    "grunt-filerev": "^2.3.1",
    "grunt-rev": "^0.1.0",
    "grunt-usemin": "^3.1.1"
  },

html页面

<!--build:css ${tg.url('css/build.css')} -->
<link rel="stylesheet" type="text/css" href="${tg.url('css/WebApp_reset.css')}" />
<link rel="stylesheet" type="text/css" href="${tg.url('css/public.css')}" />
<link rel="stylesheet" type="text/css" href="${tg.url('css/main_msg.css')}" />
<!-- endbuild -->

---

1:

blockReplacements: {
    css: function(block) {
        return '<link rel="stylesheet" href="' + block.dest + '"/>';
    }
}

2:

更换cssmin的书写形式
expand: true,
cwd: 'dist/public/css/',
src: '*.css',
dest: 'dist/public/css/'