Reinitialize state in between individual unit tests.

This changes the TestingSetup fixture to be per-unit-test rather than global.
Most tests don't need it, so it's only invoked in a few.

src/main.cpp

@@ -54,7 +54,6 @@ bool fTxIndex = false;
 bool fIsBareMultisigStd = true;
 unsigned int nCoinCacheSize = 5000;
 
-
 /** Fees smaller than this (in satoshi) are considered zero fee (for relaying and mining) */
 CFeeRate minRelayTxFee = CFeeRate(1000);
 
@@ -3085,10 +3084,31 @@ bool CVerifyDB::VerifyDB(CCoinsView *coinsview, int nCheckLevel, int nCheckDepth
 
 void UnloadBlockIndex()
 {
-    mapBlockIndex.clear();
+    LOCK(cs_main);
     setBlockIndexCandidates.clear();
     chainActive.SetTip(NULL);
     pindexBestInvalid = NULL;
+    pindexBestHeader = NULL;
+    mempool.clear();
+    mapOrphanTransactions.clear();
+    mapOrphanTransactionsByPrev.clear();
+    nSyncStarted = 0;
+    mapBlocksUnlinked.clear();
+    vinfoBlockFile.clear();
+    nLastBlockFile = 0;
+    nBlockSequenceId = 1;
+    mapBlockSource.clear();
+    mapBlocksInFlight.clear();
+    nQueuedValidatedHeaders = 0;
+    nPreferredDownload = 0;
+    setDirtyBlockIndex.clear();
+    setDirtyFileInfo.clear();
+    mapNodeState.clear();
+
+    BOOST_FOREACH(BlockMap::value_type& entry, mapBlockIndex) {
+        delete entry.second;
+    }
+    mapBlockIndex.clear();
 }
 
 bool LoadBlockIndex()