Give Ajax IM a proper web framework with Express.js (bug 17)

Start bugs 17, 12, 13

* Begin integration of Express.js grammar into Ajax IM server (bug 17)
* Add basic framework for various chat object (User, Message, Room,
  Notification) (bug 12)
* Begin bringing Ajax IM up to speed with Node.js (assisted by bug 17) (bug 13)

.gitignore

@@ -0,0 +1,2 @@
+local/*
+*.local.*