Just spaces instead of underscores

[andyneff]

Once we move to spaces instead of underscores, and allow sub sub ... commands, the search time will increase with the number of arguments in the just command executed. Even though there will be no hard limit on the the number of subs allows in a command, a soft limit would be a good idea to keep the search time down, but allow the user to increase it.

Maybe write a just target that checks for problems, and check to see if the soft limit is too low, or find a way to auto set the soft limit.