core, cmd, vendor: fixes and database inspection tool (#15)

* core, eth: some fixes for freezer

* vendor, core/rawdb, cmd/geth: add db inspector

* core, cmd/utils: check ancient store path forceily

* cmd/geth, common, core/rawdb: a few fixes

* cmd/geth: support windows file rename and fix rename error

* core: support ancient plugin

* core, cmd: streaming file copy

* cmd, consensus, core, tests: keep genesis in leveldb

* core: write txlookup during ancient init

* core: bump database version

core/rawdb/accessors_metadata.go

@@ -80,6 +80,20 @@ func WriteChainConfig(db ethdb.KeyValueWriter, hash common.Hash, cfg *params.Cha
 	}
 }
 
+// ReadAncientPath retrieves ancient database path which is recorded during the
+// first node setup or forcibly changed by user.
+func ReadAncientPath(db ethdb.KeyValueReader) string {
+	data, _ := db.Get(ancientKey)
+	return string(data)
+}
+
+// WriteAncientPath writes ancient database path into the key-value database.
+func WriteAncientPath(db ethdb.KeyValueWriter, path string) {
+	if err := db.Put(ancientKey, []byte(path)); err != nil {
+		log.Crit("Failed to store ancient path", "err", err)
+	}
+}
+
 // ReadPreimage retrieves a single preimage of the provided hash.
 func ReadPreimage(db ethdb.KeyValueReader, hash common.Hash) []byte {
 	data, _ := db.Get(preimageKey(hash))