moving the bits configuration into private state.  Needed to move the creation of the private state up so that it can be accessed during initialize()
Support running 'just' one test suite.  [4mRunning "nodeunit:just:motor" (nodeunit:just) task[24m

[4mRunning "nodeunit:tests" (nodeunit) task[24m
Testing motor.js......................................................[32mOK[39m
[32m>> [39m370 assertions passed (170ms)

[32mDone, without errors.[39m
Don't need the underscore reference anymore
taking the registry off the board, and into a private mapping