Refactoring yieldControlAction such that the SCont being switched away
from is available. This is useful for thread accountability, and in
general, something essential for debugging and optimizing user-level
schedulers.
Cleaning up tests
Testing time accounting in scheduler (ChameneosRedux). Added default
(unit) SCont-local state in newSCont function.
Added FairShare user-level scheduler. Uses heavy-weight getClockTime.