This method is called when the plugin is loaded / initialized
In our case, it'll simply store the pluginInterface reference
and register our PluginView.
Pauses the specified download and adds it to the list of downloads
that we have paused, that we can thereby recall later which
downloads we have paused when it is time to un-pause them.
Implement this interface and register with the SchedulePersistencyManager
to receive notification when the user-configured schedules have changed on disk.