Reformat API_DRAFT, rename command to listener

[madx]

I've:

• Reformated the text to wrap at 80 columns, removed trailing whitespace
• Renamed Commands to Listeners. I guess this is the best term we can find. This is also how Hubot calls it's handler scripts.

@kud, @mlbli: I'm going to comment a few lines of the draft and I need your opinion on this

[madx]

ABOOOORT