refractor: delete redundant files (#295)

* Remove obsolete index.ts files.
* Remove About Module.

Fixes #294

src/app/accounting/accounting-routing.module.ts

@@ -1,7 +1,11 @@
 import { NgModule } from '@angular/core';
 import { Routes, RouterModule } from '@angular/router';
 
-import { Route, extract } from '../core';
+/** Routing Imports */
+import { Route } from '../core/route/route.service';
+
+/** Translation Imports */
+import { extract } from '../core/i18n/i18n.service';
 
 import { AccountingComponent } from './accounting.component';
 import { FrequentPostingsComponent } from './frequent-postings/frequent-postings.component';