Drop fees by 10x due to the persistently higher exchange rate.

The last fee drop was by 5x (from 50k satoshis to 10k satoshis)
in the 0.8.2 release which was about 6 months ago.

The current fee is (assuming a $500 exchange rate) about 5 dollar
cents. The new fee after this patch is 0.5 cents.

Miners who prefer the higher fees are obviously still able to
use the command line flags to override this setting. Miners who
choose to create smaller blocks will select the highest-fee paying
transactions anyway.

This would hopefully be the last manual adjustment ever required
before floating fees become normal.

src/core.h

@@ -152,8 +152,8 @@ public:
         // to spend something, then we consider it dust.
         // A typical txout is 34 bytes big, and will
         // need a CTxIn of at least 148 bytes to spend,
-        // so dust is a txout less than 54 uBTC
+        // so dust is a txout less than 546 satoshis 
-        // (5460 satoshis) with default nMinRelayTxFee
+        // with default nMinRelayTxFee.
         return ((nValue*1000)/(3*((int)GetSerializeSize(SER_DISK,0)+148)) < nMinRelayTxFee);
     }
 

src/main.cpp

@@ -48,7 +48,7 @@ unsigned int nCoinCacheSize = 5000;
 /** Fees smaller than this (in satoshi) are considered zero fee (for transaction creation) */
 int64_t CTransaction::nMinTxFee = 10000;  // Override with -mintxfee
 /** Fees smaller than this (in satoshi) are considered zero fee (for relaying) */
-int64_t CTransaction::nMinRelayTxFee = 10000;
+int64_t CTransaction::nMinRelayTxFee = 1000;
 
 static CMedianFilter<int> cPeerBlockCounts(8, 0); // Amount of blocks that other nodes claim to have
 

src/test/transaction_tests.cpp

@@ -271,10 +271,10 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     string reason;
     BOOST_CHECK(IsStandardTx(t, reason));
 
-    t.vout[0].nValue = 5011; // dust
+    t.vout[0].nValue = 501; // dust
     BOOST_CHECK(!IsStandardTx(t, reason));
 
-    t.vout[0].nValue = 6011; // not dust
+    t.vout[0].nValue = 601; // not dust
     BOOST_CHECK(IsStandardTx(t, reason));
 
     t.vout[0].scriptPubKey = CScript() << OP_1;