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/qt/paymentserver.cpp

@@ -274,7 +274,7 @@ bool PaymentServer::ipcSendCommandLine()
         if (!socket->waitForConnected(BITCOIN_IPC_CONNECT_TIMEOUT))
         {
             delete socket;
-            socket = NULL;
+            socket = nullptr;
             return false;
         }
 
@@ -290,7 +290,7 @@ bool PaymentServer::ipcSendCommandLine()
         socket->disconnectFromServer();
 
         delete socket;
-        socket = NULL;
+        socket = nullptr;
         fResult = true;
     }
 
@@ -364,7 +364,7 @@ void PaymentServer::initNetManager()
 {
     if (!optionsModel)
         return;
-    if (netManager != NULL)
+    if (netManager != nullptr)
         delete netManager;
 
     // netManager is used to fetch paymentrequests given in bitcoin: URIs