BUG: Fixed shallow copy bug
BUG: Fixed shallow copy bug

- @danielballan: Does this need a test?  If so, any suggestions
  about what exactly would be tested?
- closes #98
- I went with the setattr/delattr method instead of deepcopy...
  seems much cheaper to do it this way

NSLS-II/dataportal,NSLS-II/dataportal,ericdill/databroker,ericdill/databroker,NSLS-II/datamuxer,ericdill/datamuxer,tacaswell/dataportal,danielballan/dataportal,tacaswell/dataportal,danielballan/datamuxer,ericdill/datamuxer,danielballan/dataportal,danielballan/datamuxer