Enhancement Request: backfill history upon panel initialization

[yoyolb]

Hello,

It would be great to have the opportunity to backfill some data upon panel refresh or initialization. How? I don't know...

• Use an other datasource (sql request, ...)?
• Keep last N messages in memory for all registered topics even if panel is not open?

Lionel;

[Drakynn]

This seems to be related to issue #36 where data is lost the moment you close the browser window.

It starts collecting again automatically whether a browser is viewing the panel or not, but gets wiped again on browser close.