Add the BFS CPU Scheduler

This incorporates the 0.413 version of the BFS CPU Scheduler created by Con Kolivas. _thalamus was kind of enough to backport some features from the 0.420 version of the scheduler as well. In addition, _thalamus also implemented a tweak that will save several CPU cycles.

Signed-off-by: Shankar <mathkid95@gmail.com>