Implemented basic priority scheduler functionality.

Code is not working, and does not attempt to handle nested donation.
Fixed priority scheduler code to not breka things.

Priority specific tests, except for alarm-priority, still fail.
Fully debugged non-donation priority.

Priority donation still doesn't work.
Finished debugging basic priority donation.

Nested donation still does not work.
advanced scheduler first push
my message
Merge branch 'proj3_advanced_scheduler' of ssh://login.cms.caltech.edu/cs/courses/cs124/teams/pintos-gmt into proj3-priority

Conflicts:
	src/threads/thread.c
	src/threads/thread.h
Fully integrated the advanced scheduler code.

All advanced scheduler tests pass in QEMU, but not Bochs. ???
design doc
Commited the design document.