show cursor on picking and other modes than draw/erase, sanity check on presets file

src/main.cpp

@@ -73,7 +73,6 @@ void destroy_window()
     main_tasklist.emplace_back([=] {
         SendMessage(hWnd, WM_USER_CLOSE, 0, 0);
     });
-    SendMessage(hWnd, WM_USER_CLOSE, 0, 0);
 }
 
 void async_lock()
@@ -826,6 +825,7 @@ int main(int argc, char** argv)
         LOG("hmd renderer terminated");
     });
 
+    SetTimer(hWnd, 1, 500, NULL);
 
     MSG msg;
     LOG("start main loop");