Merge branch 'expressjs'
Extended robot.brain to act as a general-purpose key-value store.

Additions:
 - robot.brain.set
   For storing arbitrary key, value pairs under a private namespace to avoid collisions.
 - robot.brain.ger
   For getting from store by key.

Signed-off-by: Diwank Singh Tomer <diwank.singh@gmail.com>
Made suggested style changes.

Details: https://github.com/github/hubot/pull/447
Merged Store into Brain.

As suggested by @technicalpickles here -
https://github.com/github/hubot/pull/447#issuecomment-15365257
Added documentation for key-value store.
Merge branch 'extended-brain' of https://github.com/creatorrr/hubot into creatorrr-extended-brain
Remove comments and simplify
Update README