add history functionality to commander
Those who forget history are doomed to repeat it.

Unless they really want to repeat it, but they fuck it up so bad the first time that it just doesn't work.

* Fixed history.  Commands should execute properly now.
* Added blank line when using down arrow beyond the last history item.
* Cleaned up monster conditional statement to make it more readable.
Merge pull request #15 from greeze/46349063-commander-history

add history functionality to commander