#How to build from sources :

git clone https://github.com/namecoin/namecoin
git pull origin namecoin-qt:namecoin-qt
git checkout namecoin-qt

#Make namecoin-qt
cd project; qmake; make

#Make namecoind
cd src; make

main.cpp: GetNextWorkRequired line 671
    // Go back the full period unless it's the first retarget after genesis. Code courtesy of ArtForz

    int nBlocksBack = nInterval-1;
    if(pindexLast->nHeight >= hooks->GetFullRetargetStartBlock() && ((pindexLast->nHeight+1) > nInterval))
        nBlocksBack = nInterval;

bool CTxOut::IsDust() const
{   
    // "Dust" is defined in terms of CTransaction::nMinRelayTxFee,
    // which has units satoshis-per-kilobyte.
    // If you'd pay more than 1/3 in fees
    // to spend something, then we consider it dust.
    // A typical txout is 33 bytes big, and will
    // need a CTxIn of at least 148 bytes to spend,
    // so dust is a txout less than 54 uBTC
    // (5430 satoshis) with default nMinRelayTxFee
    return ((nValue*1000)/(3*((int)GetSerializeSize(SER_DISK,0)+148)) < CTransaction::nMinRelayTxFee);
}