In merge dialog also Start-ID should be searched

In some school events, when renting 200-500 si-cards, we give to every
runner a random si-card, but a specific start number. At the read out
place, when then fill in the start number the runner is wearing. So it
would be nice if in Geco in the merge dialog you could also search after
the start number
Merge pull request #34 from yannisgu/master

Include Start-ID so that it can be lookup in the merge dialog