Add dates to front page user graph

[Kogni]

It has long been an annoyance that the user graph doesn't say which number is for what date. Sometimes people wonder if the latest number is for today or for yesterday.

[trygvis]

I'm not capable enough to do this. The libraries used are also very old (from p2k12) so it might be a better library available that might solve this today.

If it makes it easier for anybody the data can be made available as JSON instead of being embedded in HTML as it is now. Perhaps there are third party graph services that can be used to make the graph directly.

[odinho]

Or just writing that newest data point is for today, then it's also clear?

Registrert bruk inkludert i dag instead of Registrert bruk siste dager.

[odinho]

Made it clearer now.

I think this is much better than cluttering the graph with dates. People can use a calendar for that IMHO :)