Keep track of age of oldest article

[hugbug]

From forum topic Keep track of age of oldest article:

Could NZBget keep track of the oldest article successfully downloaded from each server and display the number of days?

Server 1: 750d Server 2: 2500d Server 3: 150d

Could it be added as information on the Server settings page or perhaps as a new column on the Speed Limit screen?

We also need a way to reset this statistic.