[Feature Request] Add support for silent updates

[abhiandthetruth]

Currently, the app gives notifications for every update done to an event. This could be annoying for users if someone updates the event details for a minor spelling mistake or for a minute change of text.
We can provide a silent updates feature which, updates the event but does not notifies the users. This way frequent updates would be made possible.
Also the current functionality does not suffer, as we can turn on notify by default.