do not reparent client window; fix amiwm#29

reparenting the client's window creates a few issues:
• We get bogus UnmapNotify and MapNotify events that are ultimately
  generated by amiwm itself.
• We do not get button events from the window, since its frame
  (c->parent) that we have called XGrabButtons(3) onto, is not
  its parent anymore.

To fix this, do not reparent the client window, but its frame window.
And keep the client window always inside the frame.

client.c

@@ -149,10 +149,12 @@ void checksizehints(Client *c)
 
 void open_fscrn(Client *c)
 {
-  XUnmapWindow(dpy, c->parent);
   c->fsscr = scr = openscreen(NULL, scr->root);
   c->reparenting = 1;
-  XReparentWindow(dpy, c->window, scr->back, 0, 0);
+  XReparentWindow(dpy, c->parent, c->fsscr->back, 0, 0);
+  XRaiseWindow(dpy, c->window);
+  XMoveResizeWindow(dpy, c->parent, 0, 0, c->fsscr->width, c->fsscr->height);
+  XMoveResizeWindow(dpy, c->window, 0, 0, c->fsscr->width, c->fsscr->height);
   for (Client *dialog = clients; dialog != NULL; dialog = dialog->next)
     if (dialog->leader == c)
       reparent_client(c->fsscr, dialog);
@@ -171,7 +173,9 @@ void close_fscrn(Client *c, int state)
 {
   if (c->fsscr == NULL)
     return;
-  XReparentWindow(dpy, c->window, c->parent, 4, c->scr->bh);
+  XReparentWindow(dpy, c->parent, c->scr, c->x, c->y);
+  XMoveResizeWindow(dpy, c->parent, c->x, c->y, c->pwidth, c->pheight);
+  XMoveResizeWindow(dpy, c->window, 4, c->scr->bh, c->pwidth-c->framewidth, c->pheight-c->frameheight);
   XResizeWindow(dpy, c->window, c->pwidth-c->framewidth, c->pheight-c->frameheight);
   XLowerWindow(dpy, c->window);
   scr = c->fsscr;