===== FastFlow pipeline (C++11 syntax) =====

Create the pipeline by creating an **ff_pipe** object and passing as parameters the stages:
<code>
ff_pipe<T> myPipe(stage1, stage2, ...) 
</code>

**T** is the type of the taks flowing throuhg the pipeline. 

The pipeline stages should be procedures/lambdas with signature
<code>
T* f(T*, ff_node*)
</code>
The second parameter is used by the implementation.