Reparent to the root window before deferring close

We did this before implementing the deferred close in yabridge 3.0.0. It
didn't seem necessary anymore so we got rid of it, but without this
closing an iZotope Rx plugin's editor in Renoise was guaranteed to
trigger an X11 error and crash Renoise. Doing this reparent doesn't seem
to cause any slowdown but it does at least fix the specific combination
of iZotope Rx and Renoise.

src/wine-host/editor.h

@@ -78,9 +78,13 @@ class DeferredWindow {
      *
      * @param main_context This application's main IO context running on the GUI
      *   thread.
+     * @param x11_connection The X11 connection handle we're using for this
+     *   editor.
      * @param window A `HWND` obtained through a call to `CreateWindowEx`
      */
-    DeferredWindow(MainContext& main_context, HWND window);
+    DeferredWindow(MainContext& main_context,
+                   std::shared_ptr<xcb_connection_t> x11_connection,
+                   HWND window);
 
     /**
      * Post a `WM_CLOSE` message to the `handle`'s message queue as described
@@ -92,6 +96,7 @@ class DeferredWindow {
 
    private:
     MainContext& main_context;
+    std::shared_ptr<xcb_connection_t> x11_connection;
 };
 
 /**
@@ -222,7 +227,7 @@ class Editor {
      */
     void do_xembed() const;
 
-    std::unique_ptr<xcb_connection_t, decltype(&xcb_disconnect)> x11_connection;
+    std::shared_ptr<xcb_connection_t> x11_connection;
 
     /**
      * The Wine window's client area, or the maximum size of that window. This