CORE: Fill in defaultAssumeValid from checkpoints
CORE: Fill in defaultAssumeValid from checkpoints

Simplify maintanence by making it not necessary to manually update this for each release, we update the checkpoint data anyway, get it from there.

nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official,nlgcoin/guldencoin-official