Merge branch 'master' into ab-debian

* master:
  smartd_log plugin: convert chart family to lower case
  ovpn_status_log plugin: minor fixes
  fail2bain plugin: "Currently In Jail" chart renamed
  dns_query_time plugin: replace "." with "_" in dimensions
  updated configs.signatures
  ZFS plugin for Linux; fixes #1994
  dns_query_time plugin: python readme update
  dns_query_time plugin: makefiles and python.d.conf update
  dns_query_time plugin: module configuration file added
  dns_query_time plugin: added
  added backends debugging; #2017
  fail2ban_plugin: "filterfalse" removed
  fail2ban_plugin: "Currently In Jail" chart added
  prevent a crash if loadvg chart is disabled
  Minimize reallocz usage in FreeBSD plugin
  Fix compilation error on FreeBSD 10.3
  postgres_plugin: module configuration file update
  postgres_plugin: option to exclude databases from poll added

diff --cc web/index.html
Simple merge