message: Change PPCoin mention in signed messages
  This change makes signed message incompatible with previous versions of
  Peercoin.
diff: @@ -73,7 +73,7 @@ map<uint256, set<uint256> > mapOrphanTransactionsByPrev;
  // Constant stuff for coinbase transactions we create:
  CScript COINBASE_FLAGS;
  -const string strMessageMagic = "PPCoin Signed Message:\n";
  +const string strMessageMagic = "Peercoin Signed Message:\n";
  double dHashesPerSec = 0.0;
  int64 nHPSTimerStart = 0;
  