* [NOD-338] Recover indexer if it didn't work for a while
* [NOD-338] Recover indexer if it didn't work for a while
* [NOD-338] Recover indexer if it didn't work for a while
* [NOD-338] Add tests and move blockidhash.go to blockdag package
* [NOD-338] Delete index current block id when dropping index, and do some refactoring
* [NOD-338] Change comments
* [NOD-338] Change recover error messages
* [NOD-338] Fix comments
* [NOD-338] Fix comments and fix test name