Called when the Pluggable is enabled (activated) or disabled (deactivated).
activation will be called at the start of the program if the user previously enabled/disabled it as well as during program execution if the user changes its state. Note that disabling a Pluggable does not require destroying existing resources or objects the Pluggable has previously handed off to the host.
This is purely informational. The Pluggable should acquire any long-term resources it may be holding onto here, or wait until an extension-specific call is made to it.