NodeManager feature request

Marc requested the ability to turn off bwlimits in NM.  Also, since some nodes will have gigE connections to the outside world, moving from byte limits measured in KB to MB would probably be a good idea.

 NM in head is currently broken.  IIRC, dhozac was the last to play with it and I'm not certain what he did and didn't do.  I've been careful to merge changes I've made to the branch into head so, hopefully, the code isnt THAT different.  Regardless, I foresee at least a week of testing a tweaking before i can sign off on it.