Style improvements (#2475)

* HooksRouter is enabled by default

* Adds middleswares on PromiseRouter, fixes #2410

* Move testing line to helper

* Modernize middlewares.js

* Moves DB uniqueness initialization to DBController, modernize

* Moves testing related code to spec folder

* remove unused _removeHook function

* Adds tests, docs for Analytics and improvements

* nit

* moves back TestUtils

src/Controllers/UserController.js

@@ -4,7 +4,6 @@ import AdaptableController from './AdaptableController';
 import MailAdapter         from '../Adapters/Email/MailAdapter';
 import rest                from '../rest';
 
-var DatabaseAdapter = require('../DatabaseAdapter');
 var RestWrite = require('../RestWrite');
 var RestQuery = require('../RestQuery');
 var hash = require('../password').hash;