Improve Slot Allocation

~~TASK:Garrett Koller?~~ Make Condor's slot allocation “nicer”.

• Fix the RANK function so that jobs are allocated in a breadth-first manner instead of a depth-first manner. Evenly distribute the work between machines. Ex: 4 submitted jobs on 4 machines with 2 slots each should run with one job on each of the 4 machines instead of all the jobs running on the first two machines and none on the second two machines. Use the TotalLoadAvg variable in the RANK function to take the total CPU usage into account.