Added CPS Fib in cpsexamples package. It is 100x faster than pCPS Fib :-|

+ Removed the synchronized block in Fib.java and collected all the
  subtasks and constraints before adding them in one go (so as to
  avoid unnecessary synchronization). No speedup, though.
+ Added Main.java where we measure all the different Fib variants.
+ Removed unnecessary calls to vertexSet() in Scheduler assert
  statements. No speedup, though.
Added id in Activation toString().

This way we can differentiate between Activations.