scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL

-BEGIN VERIFY SCRIPT-
sed -i 's/\<NULL\>/nullptr/g' src/*.cpp src/*.h src/*/*.cpp src/*/*.h src/qt/*/*.cpp src/qt/*/*.h src/wallet/*/*.cpp src/wallet/*/*.h src/support/allocators/*.h
sed -i 's/Prefer nullptr, otherwise SAFECOOKIE./Prefer NULL, otherwise SAFECOOKIE./g' src/torcontrol.cpp
sed -i 's/tor: Using nullptr authentication/tor: Using NULL authentication/g' src/torcontrol.cpp
sed -i 's/METHODS=nullptr/METHODS=NULL/g' src/test/torcontrol_tests.cpp src/torcontrol.cpp
sed -i 's/nullptr certificates/NULL certificates/g' src/qt/paymentserver.cpp
sed -i 's/"nullptr"/"NULL"/g' src/torcontrol.cpp src/test/torcontrol_tests.cpp
-END VERIFY SCRIPT-

src/test/test_bitcoin.cpp

@@ -140,7 +140,7 @@ TestChain100Setup::CreateAndProcessBlock(const std::vector<CMutableTransaction>&
     while (!CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus())) ++block.nNonce;
 
     std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(block);
-    ProcessNewBlock(chainparams, shared_pblock, true, NULL);
+    ProcessNewBlock(chainparams, shared_pblock, true, nullptr);
 
     CBlock result = block;
     return result;