Changelog:
* Spawn: don't loop forever on ECHILD
* Do not fail locking if there is a stale lockfile Tomas Mraz)
* Use lckpwdf if prefix not set (Tomas Mraz)
* Build: check correct DocBook version (Jan Tojnar)
* Usermod: Print 'no changes' to stdout, not stderr (Serge Hallyn)
* Add support for btrfs subvolumes for home (Adam Majer)
* Fix chpasswd long line handling (Nathan Ruiz)
* Use secure_getenv for gettime (Chris Lamb)
* Make sp_lstchg reproducible (Chris Lamb)
* Do not crash commonio_close if db file is not open (Tomas Mraz)
* Don't flush nscd and sssd cache in read-only mode (Charlie Vuillemez)
* French manpage update (Alban VIDAL)
* Fix manpage defaults for SUB_UID/GID_COUNT (Tomas Mraz)
* Sync po files from shadow.pot (Alban VIDAL)
* Usermod: guard against unsafe chown of homedir contents (Tomas Mraz)
* Add LASTLOG_UID_MAX to login.defs (Tomas Mraz)
* new[ug]idmap file capabilities support (Giuseppe Scrivano and Christian Brauner)
* Fix segfault in useradd (Tomas Mraz)
* Coverity issues (Tomas Mraz)
* Flush sssd caches (Jakub Hrozek)
* Log UID in nologin (Vladimir Ivanov)
* run pam_getenvlist after setup_env in su.c (Michael Vogt)
* Support systems with only utmpx (A. Wilcox)
* Fix unguarded ENABLE_SUBIDS code (Jan Chren (rindeal))
* Update po/zh_CN translation (Lion Yang)
* Create parent dirs for useradd -m (Michael Vetter)
* Prevent usermod segv
* Fix usermod crash (fariouche)