* docs/reference/glib/glib-sections.txt:
* glib/glib.symbols:
* glib/gthreadpool.[ch]:
- Added new API g_thread_pool_get_idle_time() and
g_thread_pool_set_idle_time(). (#324228).

* tests/threadpool-test.c:
- Updated test case to do thread pool sorting, thread pool with
no sorting and a thread pool with idle thread timeouts.