Origins no longer have a lattice structure.
A unique id is associated to each created origin. When multiple origins can
be associated to a value, we keep the oldest origin (according to their ids).

By default:
- removes final message "Done for function main".
- removes messages about the initial state computation.

In all files, all occurrences of "[eva] done for function" have been replaced
by "[eva] Done for function".

- always remove FC's internal attribute everywhere before deciding whether
  a cast is needed.
- ACSL and C decisions to cast are similar
- only unroll type for checking equality. If a cast is needed, keep
  typedef (if any) as target

attributes that are completely internal to Frama-C and do not have any impact
on the semantics of the underlying value should not lead to a cast node.