Support for fields querystring parameter

[dumbo0001]

I want to retrieve detailed information about running builds (e.g. estimated time) which isn't returned by default from the TeamCity's REST API.
Using the fields querystring parameter it is possible to configure the returned fields in the response. An example API call will be:
http://localhost:8111/app/rest/builds/?locator=running:true&fields=count,build(id,status,state,running-info)

Please add support for passing the fields to return in the response.