Send multiple inv messages if mempool.size > MAX_INV_SZ

Changes the response to the 'mempool' command so that if
the memory pool has more than MAX_INV_SZ transactions (50,000)
it will respond with multiple 'inv' messages.

src/main.cpp

@@ -3814,8 +3814,10 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
             if ((pfrom->pfilter && pfrom->pfilter->IsRelevantAndUpdate(mempool.lookup(hash), hash)) ||
                (!pfrom->pfilter))
                 vInv.push_back(inv);
-            if (vInv.size() == MAX_INV_SZ)
+            if (vInv.size() == MAX_INV_SZ) {
-                break;
+                pfrom->PushMessage("inv", vInv);
+                vInv.clear();
+            }
         }
         if (vInv.size() > 0)
             pfrom->PushMessage("inv", vInv);