* xterm.h (x_catch_errors) Return value changed to void.
(x_uncatch_errors): Unused count argument deleted.
* xterm.c (x_catch_errors): Don't use record_unwind_protect, since
it can be called in a signal handler.
(x_catch_errors_unwind): Function deleted.
(x_uncatch_errors): Deallocate last x_error_message_stack struct.
(x_check_errors): Call x_uncatch_errors before signalling error.
(x_load_font, x_term_init, XTmouse_position, handle_one_xevent)
(x_connection_closed, x_list_fonts): Use new versions of
x_catch_errors and x_uncatch_errors.