Merge #7840: Several performance and privacy improvements to inv/mempool handling

b559914 Move bloom and feerate filtering to just prior to tx sending. (Gregory Maxwell)
4578215 Return mempool queries in dependency order (Pieter Wuille)
ed70683 Handle mempool requests in send loop, subject to trickle (Pieter Wuille)
dc13dcd Split up and optimize transaction and block inv queues (Pieter Wuille)
f2d3ba7 Eliminate TX trickle bypass, sort TX invs for privacy and priority. (Gregory Maxwell)

src/txmempool.h

@@ -511,6 +511,7 @@ public:
                         std::list<CTransaction>& conflicts, bool fCurrentEstimate = true);
     void clear();
     void _clear(); //lock free
+    bool CompareDepthAndScore(const uint256& hasha, const uint256& hashb);
     void queryHashes(std::vector<uint256>& vtxid);
     void pruneSpent(const uint256& hash, CCoins &coins);
     unsigned int GetTransactionsUpdated() const;