version update

 - restored 'SatoshiClone' client name
 - v x.y.z.0 won't be shortened as v x.y.z anymore
 - set version to 0.8.4.0 (until tags are applied when merged into
   master branch)
checkpoints.

 - 191101 & 196542 mainnet checkpoints added.
logging & 192240 block retarget update.

 - not using printf() anymore ; switched to LogPrintf() too
 - 192240 block retarget update (came with build 0.8.0.2)