Allchanlocal

local allchannel experiment
we could avoid this by doing
```
local_instance_cmd = "process_guard.py -c allchannel_client.py -c allchannel_client.py -c allchannel_client.py -c allchannel_client.py -c allchannel_client.py -t $EXPERIMENT_TIME -m $OUTPUT_DIR/local/local -o $OUTPUT_DIR "
```
instead

This way we don't need a new config option (```local_output_dir```) and its logic.

Other than that, it looks fine.