- "modelnet" parameter in cfg is now a no-op
- "modelnet_order" parameter in cfg is required,
  listing order in which networks are indexed to
  the model
- modified "model_net_set_params" signature
- updated tests to use the new interface

Adding collective modeling functions in model-net (currently only dragonfly/torus models support it)

- NOTE: shim just forces packet size to a huge number

- NOTE: the current scheduling policy of FCFS is hard-coded, this will change
  in future revisions
- NOTE: random number generation has changed due to the differences in
  scheduling and packet ordering. Hence, results may be slightly different from
  runs prior to this commit

- currently stupid, stats don't really mean
  anything when pulling
- enable manually by setting do_pull = 1 (no
  cmdline option yet)

- pull itself not yet tested

Instead of specifying the loggp config file path relative to the
path of the respective executable file, you now must specify it
relative to the path of the master config file.