This API function informs a plugin about the change of state of another plugin:
function PLG_pluginStateChange($type, $status)
$type is the name of the plugin whose state has just changed.
$status informs about the plugin's new state and can be one of the following:
Please note that notifications for the (new) state of 'installed', 'uninstalled', or 'upgraded' are unreliable, as these may happen in the plugin's install script, outside of Geeklog's control (for plugins not using Plugin Autoinstall or Plugin Auto-Uninstall).
PLG_enableStateChange, this function is called after the state change has happened.