I finally got rid from the last pieces of GPL'ed code in my own miner and can now release it to the public. This miner is not free, a royalty of 1/8 (12.5%) is deducted from every mined block. (Coinbase transaction have 2 outputs, so I get my fee at exactly the same moment you'll get your coins).
Download link:https://mega.co.nz/#!QMMEFBYY!AgH4OGrKaRHkRjiVfVXXzxBHbTIlgdD5o3ak2VFuU78
Edit quarkcoin.conf (or Offering.conf, or securecoin.conf) file of your wallet to enable solo-mining, put your own username and password there:
listen=1
rpcallowip=127.0.0.1
rpcuser=username
rpcpassword=password
rpcport=8772
server=1
Edit sm.cmd from downloaded archive, put your own username, password and wallet address there:
smelter -o
http://127.0.0.1:8772 -u username -p password -a QNiGvoYctyMwzV1ZjNbjhEoKdQVzFKsmVw
This is pre-alpha software, expect all kinds of bugs to be found, don't hesitate to report it here!
NVidia and old/rare AMD cards are not supported. Please, give me some time to iron out bugs

Where is this quarkcoin.conf file located exactly? Searching the computer finds nothing. Nothing in the wallet data folder or the folder that launches the wallet executable.