Remove spurios opret in tx builder, don't wait forever for blocks before mining, add delay to getblocktemplate

src/main.h

@@ -228,8 +228,10 @@ void ThreadScriptCheck();
 void PartitionCheck(bool (*initialDownloadCheck)(), CCriticalSection& cs, const CBlockIndex *const &bestHeader, int64_t nPowTargetSpacing);
 /** Check whether we are doing an initial block download (synchronizing from disk or network) */
 bool IsInitialBlockDownload();
-/** Check if the daemon is in sync */
-bool IsInSync();
+/** Check if the daemon is in sync, if not, it returns 1 or if due to best header only, the difference in best
+ * header and activeChain tip
+ */
+int IsNotInSync();
 /** Format a string that describes several potential problems detected by the core */
 std::string GetWarnings(const std::string& strFor);
 /** Retrieve a transaction (from memory pool, or from disk, if possible) */