Call after (or done) callback after task ends

I have developement task like
`grunt.registerTask("dev", ["server", "jshint", "copy:dev", "coffeelint", "coffee", "watch"])`
which will start server and copy files from /src into /public where is index.html and server pointed.

This will copy (or compile) lot of files into public directory.
After my work session I want to cleanup this directory. I looked for something like `after`, `done` or `teardone` callback which will run some task after the main task is killed, or finished.

``` javascript
var task = grunt.registerTask("dev", ["server", "jshint", "copy:dev", "coffeelint", "coffee", "watch"])

// With Deferred API this will be called when main task is break, killed, finished or end from any other reason
task.always(function() {
grunt.task.requires('cleanup');
})
```

I tried to check sources, but did not find anything like this. Is there any way, how to do that, or is it planning feature?