Merge branch 'collectd-5.6'

diff --cc configure.ac
Simple merge

diff --cc src/battery.c
Simple merge

diff --cc src/daemon/common.c
Simple merge

diff --cc src/openvpn.c
Simple merge

diff --cc src/powerdns.c
Simple merge

diff --cc src/utils_format_graphite.c
Simple merge

diff --cc src/write_kafka.c
Simple merge

diff --cc src/zfs_arc.c
Simple merge