[!TARGET_API_MAC_CARBON]: Don't include Scrap.h.

[!TARGET_API_MAC_CARBON]: Don't include Scrap.h.
(Selection): Move typedef to macgui.h.
(Vselection_converter_alist, Qmac_scrap_name, Qmac_ostype)
(Vmac_apple_event_map, Qmac_apple_event_class, Qmac_apple_event_id):
Make variables non-static.
(Vmac_dnd_known_types) [TARGET_API_MAC_CARBON]: Likewise.
(mac_handle_apple_event, cleanup_all_suspended_apple_events):
Make functions non-static.
(Vmac_service_selection) [MAC_OSX]: Likewise.
(mac_get_selection_from_symbol, get_flavor_type_from_symbol)
(mac_valid_selection_target_p, mac_clear_selection)
(mac_get_selection_ownership_info, mac_valid_selection_value_p)
(mac_put_selection_value, mac_selection_has_target_p)
(mac_get_selection_value, mac_get_selection_target_list)
(init_apple_event_handler, install_drag_handler, remove_drag_handler):
Move functions to mactoolbox.c.
(mac_do_track_drag, mac_do_receive_drag) [TARGET_API_MAC_CARBON]:
Likewise.
(copy_scrap_flavor_data, mac_handle_service_event)
(install_service_handler) [MAC_OSX]: Likewise.
(syms_of_macselect) <Vmac_dnd_known_types>:
Use mac_dnd_default_known_types.