Added PR request

[ojnadjarm]

Hi I'm from Moodle US, some of our clients were having issues with this pluging due to the event handling, when too much events. It seems to be causing performance issues, so we added a way to run the events trought adhoc task, you can enable the feature or leave it with the current behaviour, we decided this could be helpful so we are sharing it with the comunity if you want to add it.
#54