FEATURE #1337: add file upload

This commit registers new items into admin menu and adds functionality for uploading files.

app/Http/routes.php

@@ -90,12 +90,16 @@ Route::group([
          ->name('history.diff');
 
     // uploader methods
-    Route::post('upload/file', 'Uploader@postFile')
+    Route::get('upload/file', 'UploadFile@getFile')
          ->name('upload.file');
 
     Route::post('upload/image', 'Uploader@postImage')
          ->name('upload.image');
 
+    // uploader methods
+    Route::post('upload/file', 'UploadFile@postFile')
+         ->name('upload.postFile');
+
     // custom fields
     // ------------------------------