Add new field to CrawlDatum

[Koch Martina]

Hi all,

I'd like to add a new field to the CrawlDatum to capture the date when an URL 
was found first. The field should be called FoundFirst. Can anyone tell me 
which classes I need to modify in order to achieve this? In my opinion, it 
should be sufficient to change the CrawlDatum and CrawlDbReader class, but I 
think, I've missed something beacause the CrawlDbMerger crashes now. I know 
that I lose the compatibility to Nutch, but still...

Thanks in advance.

Kind regards,
Martina