Decrease minimum TX fee to 0.0005 BTC.

src/main.h

@@ -19,7 +19,7 @@ static const unsigned int MAX_BLOCK_SIZE_GEN = MAX_BLOCK_SIZE/2;
 static const int MAX_BLOCK_SIGOPS = MAX_BLOCK_SIZE/50;
 static const int64 COIN = 100000000;
 static const int64 CENT = 1000000;
-static const int64 MIN_TX_FEE = CENT;
+static const int64 MIN_TX_FEE = 50000;
 static const int64 MAX_MONEY = 21000000 * COIN;
 inline bool MoneyRange(int64 nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
 static const int COINBASE_MATURITY = 100;