* magit.el (magit-quit-window): Fix Issue #825, reset
  magit-previous-window-configuration and not
  magit-restore-window-configuration.
* magit.el (magit-buffer-switch): Fix Issue #825, check all magit
  buffers.
(magit-quit-window): No need to restore magit-previous-window-configuration.
* magit.el (magit-buffer-switch): Keep fixing Issue #825, check if
  window is visible before poping to magit buffer.