Changes to remove Feval calls from GUI under NS.

Changes to remove Feval calls from GUI under NS.
* nsterm.h: Move KEY_NS_... definitions here from nsterm.m.  Add
NS_TOGGLE_TOOLBAR, NS_PUT_WORKING_TEXT, NS_UNPUT_WORKING_TEXT.
Remove NS_INSERT_WORKING_TEXT, NS_DELETE_WORKING_TEXT.

* nsterm.m: Move KEY_NS_... definitions to nsterm.h.
(EmacsView-toggleToolbar:): Use KEY_NS_TOGGLE_TOOLBAR.
(EmacsView-setMarkedText:,-deleteWorkingText:): Use NS_TEXT_EVENT
instead of NON_ASCII_KEYSTROKE_EVENT.
(EmacsApp-terminate:): Use KEY_NS_POWER_OFF instead of Feval.
(EmacsApp-applicationShouldTerminate:): Query user.
(EmacsPreferencesController-runHelp:): Use KEY_NS_INFO_PREFS
instead of Feval.

* termhooks.h (NS_TEXT_EVENT): New event type under HAVE_NS.

* keyboard.c (kbd_buffer_get_event): Check for it.
(keys_of_keyboard): Define lispy keys for
ns-put/unput-working-text.

* nsmenu.m (ns_popup_dialog): Resync window setting with X and W32
versions.
(EmacsDialog-runDialogAt:): Use NSModalPanelRunLoopMode.