Refactor and advancements

- Drops mailController, centralized in UserController
- Adds views folder for change_password
- Improves PromiseRouter to support text results
- Improves PromiseRouter to support empty responses for redirects
- Adds options to AdaptableController
- UsersController gracefully fails when no adapter is set
- Refactors GlobalConfig into same style for Routers

src/Adapters/Email/MailAdapter.js

@@ -1,5 +1,6 @@
 export class MailAdapter {
   sendVerificationEmail(options) {}
+  sendPasswordResetEmail(options) {}
   sendMail(options) {}
 }