put back changes removed in sha: 1cb82084 and sha:76c21c6e

(i was on the wrong branch)

Indeed, the silent value was missing, which was blocking luciole

and attach  the pid to  the list of neighbors  of returned by  the get
function. Indeed, this is needed in some anomymous (or semi-anonymous)
algorithms, such as the k-clustering.

also, start the first step at 0  instead of 1. Otherwise, with -cd, we
get more  steps than  moves. Indeed,  the first step  is not  really a
step; it just contain the initial state values.

It now takes  as first argument the whole list  of processes (not only
the enabled ones).

In  Algo.pf_info, the  action  field  is now  an  option  type (if  is
correspond to a process that has not been activated).

nb: does not really work yet.

nb: I needed to  split Main to avoid a Module self-loop  (as I need to
use do_step in Daemon).