added controller for cookie refresh
sending the cookieMaxAge to the client
computed when the last AJAX controller call was made
Implemented client side logic for keeping the cookie  updated.
Updated documentation for the client side part (Rain-549 Prevent cookie from being deleted).
made SocketHandler a singleton
added jsdoc comments
refactored socket handler
Socket Handler unit tests
updated docs
Merge pull request #76 from rainjs/topic-cookie

Topic cookie