Performance improvements and bug fixes

Handle language when forming NQuad. Move the fp mod earlier in the process, to avoid paying for ToEdge() function call.

Aync writes to RocksDB are 1000x faster than sync writes. We don't need to do synchronous writes because we do sync writes on commit logs

Fix a bug due to which we were unable to retrieve xids.

Batch write while merging

Tool to debug posting lists in RocksDB

RocksDB merge in go

Change log output