lecture 23 -- buddy memory management

we looked at the detailed definition of the buddy system as presented
in the wikipedia

http://en.wikipedia.org/wiki/Buddy_memory_allocation

walked thru their example of allocations and deallocations.

talked thru allocation algorithm, including recursive splitting.

got into de-alloc discussion.  two adjacent buddies should be
combined, but not across power of 2 addr boundaries.

did not fully figure out how to do this.  definitely, all the required
info is contained in allocation location (address) and block size.