Buffered Ports 

Re-issue of pull request https://github.com/planthaber/rock-webapp/pull/11 against master
> Ok, it looks like Orocos.name_service.each_task is not an Ruby array, but a c call. 

It should actually not be an array but an enumerator.

The pattern ruby-side is

```
 return enum_for(__method__) if !block_given?
```