shadowm@reicore:~/src/wesnoth$ grep -LRI 'horizontal_alignment\s\*=\s\*"\?center"\?' data/gui/default/window/
data/gui/default/window/simple_item_selector.cfg
data/gui/default/window/mp_connect.cfg
data/gui/default/window/formula_debugger.cfg
data/gui/default/window/editor_resize_map.cfg
data/gui/default/window/mp_create_game_set_password.cfg
data/gui/default/window/editor_set_starting_position.cfg
data/gui/default/window/gamestate_inspector.cfg
data/gui/default/window/game_save_overwrite.cfg
data/gui/default/window/language_selection.cfg
data/gui/default/window/mp_method_selection.cfg
data/gui/default/window/lobby_player_info.cfg
data/gui/default/window/mp_cmd_wrapper.cfg
data/gui/default/window/game_delete.cfg
data/gui/default/window/addon_connect.cfg
data/gui/default/window/data_manage.cfg
data/gui/default/window/folder_create.cfg
data/gui/default/window/title_screen.cfg
data/gui/default/window/addon_description.cfg
data/gui/default/window/mp_create_game.cfg
data/gui/default/window/campaign_difficulty.cfg
data/gui/default/window/mp_change_control.cfg
data/gui/default/window/game_save_oos.cfg
data/gui/default/window/game_save_message.cfg
data/gui/default/window/mp_server_list.cfg
data/gui/default/window/debug_clock.cfg
data/gui/default/window/tooltip_large.cfg
data/gui/default/window/editor_generate_map.cfg
data/gui/default/window/network_transmission.cfg
data/gui/default/window/addon_uninstall_list.cfg
data/gui/default/window/mp_host_game_prompt.cfg
data/gui/default/window/editor_settings.cfg
data/gui/default/window/message.cfg
data/gui/default/window/lobby_main.cfg
data/gui/default/window/edit_label.cfg
data/gui/default/window/transient_message.cfg
data/gui/default/window/unit_create.cfg
data/gui/default/window/game_load.cfg
data/gui/default/window/chat_log.cfg
data/gui/default/window/wml_message.cfg
data/gui/default/window/mp_login.cfg
data/gui/default/window/game_save.cfg
data/gui/default/window/unit_attack.cfg
data/gui/default/window/editor_new_map.cfg
data/gui/default/window/campaign_dialog.cfg
data/gui/default/window/addon_list.cfg