Plugin: Schedule change alert

[glaubinix]

I was just thinking that it might be useful to display some sort of alert if the schedule changes. I remember that at jsconfeu there was a talk not yet announced in the beginning (or at least not added to the spreadsheet) and I only saw it later by accident.

Implementation: We could simply diff the data from the local storage to the data fetched from the server. Some things should be fairly easy to diff like "Talk was moved to room X" or "Talk X was cancelled".

This could be done with a simple box at the bottom of the page.

[BattleRattle]

👍

[glaubinix]

@BattleRattle I just pushed a new branch called "change-notify" could you maybe have a look at it and tell me what you think?

Change detection is working already, design, text and tests still missing.

Unsolved problems:
-create hash or other form of useful object key for comparison (instead of JSON :))
-this plugin now has a plugin dependency on local-storage and needs to be initialized before local-storage, how should we handle something like that?