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

spec/MockEmailAdapter.js

@@ -1,3 +1,5 @@
 module.exports = {
-  sendVerificationEmail: () => Promise.resolve();
+  sendVerificationEmail: () => Promise.resolve(),
+  sendPasswordResetEmail: () => Promise.resolve(),
+  sendMail: () => Promise.resolve()
 }