Add configurable graceperiod at end of events

[bot190]

Add a grace period at the end of an event where it remains active so that users can signout. This should be configurable in the config file, and default to 2 hours (I think)

[msoucy]

Don't forget a separate configurable "early arrival" time

[bot190]

I've already implemented the early arrival part of this (merged directly into main shh)

[msoucy]

Press X to doubt

[bot190]

Yeah... I've lost this change. We need 2 new config options to add extra time around events to allow users to sign-in.

1. Before events
2. After events

[bot190]

Completed by #91