* issue #140: expose internal constants to allow changing default
timeouts and polling intervals.
* issue #141: add PID of expired process to ProcessExpired exception.
* Add pool decorators parameter allowing to provide a PebblePool
as executor for the decorated functions.
* issue #137: reset SIGTERM default handler to child processes.
* Include concurrent and asynchronous modules as top-level packages.
* Improve type hinting logic.
* Refactor internal logic: remove code duplication.
OBS-URL: https://build.opensuse.org/package/show/devel:languages:python/python-Pebble?expand=0&rev=34
