Prosa v0.4

Once abstract RTA, self-suspension model, and a multiprocessor-compatible work-conservation definition have been merged:

• Change module paths 
rt.foo… ➔ rt.classic.foo…
• Change module paths
 rt.restructuring.bar… ➔ rt.bar…
• Tag and release Prosa v0.4 and upload package to OPAM.


See also: #45 (closed)