Added CallbackApp to better access backend.Backend from with in an App

Fixed issues with CORS not being able to do an OPTIONS request
Fixed folders not being processed properly.
Fixed some other issues.

internal/cdr/backend.go

@@ -17,7 +17,7 @@ type CDRBackend struct {
 	db   *mongo.Database
 }
 
-func NewBackend(back *backend.Backend, db *mongo.Database) *CDRBackend {
+func NewBackend(db *mongo.Database) *CDRBackend {
 	go func() {
 		for range time.Tick(time.Hour) {
 			log.Println("CDR: Deleting expired dice")
@@ -29,8 +29,7 @@ func NewBackend(back *backend.Backend, db *mongo.Database) *CDRBackend {
 		}
 	}()
 	return &CDRBackend{
-		back: back,
-		db:   db,
+		db: db,
 	}
 }
 
@@ -46,6 +45,10 @@ func (b CDRBackend) CrashTable() backend.CrashTable {
 	return db.NewMongoCrashTable(b.db.Collection("crashes"), b.db.Collection("crashArchive"))
 }
 
+func (b *CDRBackend) AddBackend(back *backend.Backend) {
+	b.back = back
+}
+
 func (s CDRBackend) AddCrash(cr backend.IndividualCrash) bool {
 	res := s.db.Collection("versions").FindOne(context.Background(), bson.M{"version": cr.Version})
 	return res.Err() != mongo.ErrNoDocuments