bitkeeper revision 1.1044 (40ec19236iHRt47R5UsW46zQ42dHIw)

bitkeeper revision 1.1044 (40ec19236iHRt47R5UsW46zQ42dHIw)

Implementation of a new scheduler. Based on BVT (Borrowed Virtual Time) but trying to give more fair allocation of CPU for diverse environments (CPU-bound domains running against I/O bound ones). For that reason I called it Fair BVT (or FBVT for short). The BVT implementation gave the basic implementation. This changeset contains also the interface to control the scheduler. Unfortunatelly the contex switch allowance cannot be changed yet (a bug). The parameters introduced in the scheduler are likely to change in near future (after running tests).