refactor(naming): harmonize controller and route file names

- Delete product.controller.js, merge unique functions into products.controller.js
- Rename user.controller.js → users.controller.js, user.routes.js → users.routes.js
- Remove dead herowars/herowars.routes.js reference from herowars index
- Update all import paths accordingly

src/routes/api/herowars/index.js

@@ -2,7 +2,6 @@ var routes = require('express').Router();
 
 routes.use('/clans', require('./clans.routes'));
 routes.use('/members', require('./members.routes'));
-routes.use('/herowars', require('./herowars.routes'));
 
 routes.use(function (err, req, res, next) {
     if (err.name === 'ValidationError') {