qt: GUI for conflicted transactions

- Exclamation mark icon for conflicted transactions
- Show mouseover status for conflicted transactions as "conflicted"
- Don't show inactive transactions on overview page overview

src/qt/transactionrecord.cpp

@@ -183,7 +183,11 @@ void TransactionRecord::updateStatus(const CWalletTx &wtx)
     }
     else
     {
-        if (GetAdjustedTime() - wtx.nTimeReceived > 2 * 60 && wtx.GetRequestCount() == 0)
+        if (status.depth < 0)
+        {
+            status.status = TransactionStatus::Conflicted;
+        }
+        else if (GetAdjustedTime() - wtx.nTimeReceived > 2 * 60 && wtx.GetRequestCount() == 0)
         {
             status.status = TransactionStatus::Offline;
         }