Made vast changes to preemption side and added caching to ker_get_module for
the normal SOS.
- curr_priority is stored as a global var
- changed sched_msg_alloc, much simpler now
- check for null in do_dispatch
- singificantly modified timer_interrupt.
- Made it non reentrant with interrupts enabled.
- Dispatches msgs right away.
- The profiler has to be updated to meet the criteria.
git-svn-id: svn+ssh://projects.nesl.ucla.edu/projects/subversion/public/sos-2x/trunk@565 41346f4f-9218-0410-8fd7-88ad852d3538