Watch task for grunt assemble using grunt-newer (https://github.com/tschaub/grunt-newer)

gistfile1.js

watch: {
    assemble: {
        files: ['<%= app.app %>/*.html', '!<%= app.app %>/<%= app.templates %>/{,**/}*'],
        tasks: ['newer:assemble:server']
    },
    assemble_templates: {
        files: ['<%= app.app %>/<%= app.templates %>/{,**/}*.html', 'data.json'],
        tasks: ['assemble:server']
    },
    compass: {
        files: ['<%= app.app %>/**/*.{scss,sass}'],
        tasks: ['compass:server']
    },
    livereload: {
        files: [
            '<%= app.tmp %>/**/*.html',
            '<%= app.tmp %>/**/*.css',
            '<%= app.app %>/**/*.js'
        ],
        options: {
            livereload: true
        }
    }
}