2020-11-08: initial release
2021-02-25: rewrite for cmk 2.0
2021-09-11: added WATO, cleanup
2022-10-23: fixed warning on upgrade "non-empty params vanished" for discovery_chassis and discovery_sgms
2022-11-17: added woraround for wrong snmp data for grade/maxgrade in R81.x
2022-11-30: WATO: fixed CheckParameterRulespecWithoutItem (from CheckParameterRulespecWithItem)
2023-05-30: moved gui files to ~/local/lib/chek_mk/gui/plugins/...