Fix: the Register.diameter returned the links number (introduced in sha:40eece7c)

- add sub_tree_size, parent, is_in_tree, is_out_tree
- fix height (was only working for out-trees)
- a predessors to Topology.t
- refactor a lot of strange things in the code
  - in the use of hashtbl in particular

Fix: the seed init should be done *before* the process init (otherwise there is no randomness in the initial configuration!)

Fix a bug in the RIF data output: enable and trigger actions order was not the same in value and in the declaration

Drive rdbg tests in a more portable way

Closes #16

See merge request !12

Fixes #16

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

add a  test sin the CI  to make sure I  don't miss simca break  in the
future ! (I was only testing simca using the docker version of sasa).