Unit application library.

Library now used in all language modules.
Old 'nxt_app_*' code removed.

See src/test/nxt_unit_app_test.c for usage sample.

src/nxt_worker_process.c

@@ -19,13 +19,10 @@ static void nxt_worker_process_sigterm_handler(nxt_task_t *task, void *obj,
 static void nxt_worker_process_sigquit_handler(nxt_task_t *task, void *obj,
     void *data);
 
-
 nxt_port_handlers_t  nxt_app_process_port_handlers = {
-    .quit         = nxt_app_quit_handler,
     .new_port     = nxt_port_new_port_handler,
     .change_file  = nxt_port_change_log_file_handler,
     .mmap         = nxt_port_mmap_handler,
-    .data         = nxt_app_data_handler,
     .remove_pid   = nxt_port_remove_pid_handler,
 };