Sync service from oslo-incubator
This sync includes changes that are required to fix handling
of SIGHUP in Neutron.
The following changes and bugfixes are included:
d24b658 Revert "Optimization of waiting subprocesses in ProcessLauncher"
593005b ProcessLauncher: reload config file in parent process on SIGHUP
f29e865 Store ProcessLauncher signal handlers on class level
bf92010 Optimization of waiting subprocesses in ProcessLauncher
Change-Id: If0aab4e8978422346f6ba4c9e6272cdaf39db6cb
Closes-Bug: #
1433142
Related-Bug: #
1276694