Add Category controller and update perform
Integrated category controller for all category functions
Merge branch 'master' of https://github.com/jiongbozhang/NodeAPI

Conflicts:
	server.js
Merge branch 'master' of https://github.com/jiongbozhang/NodeAPI
Merge branch 'master' of https://github.com/jiongbozhang/NodeAPI
Merge branch 'master' of https://github.com/jiongbozhang/NodeAPI
Add Facebook imports to prepare for FB integration
Added passport-facebook middleware for future user login/account integration with facebook.