Modify icon in demo participation and last submission columns.

[tstephen]

There is an unintended implication at the start of a year that participation is less than up to date by displaying Amber icons in these columns. Decision taken 05 Jan 23 was:

1. Set green icon manually for the participation column as near as possible to the time of the demo. In other words all participating in 2022 would remain green until the 2023 demo occurs.
2. Allow last submission to be valid a whole year. For example Dec 22 submissions are currently marked out of date but it makes little sense to redo them so soon. Hence submission anytime in 2022 will now be considered current until 31 Dec 23