move logging.h to root directory
move traceback files to root directory
adapt logging.h include dir
adapt logging.h include dir
adapt include dir
FOLLY_FINAL and FOLLY_OVERRIDE
IOBuf benchmark suit
Cursor scoped in namespace io
use of io::Cursor
io::Cursor test case
Hash function and MapUtil
Random: randomNumberSeed()
Compression: with lz4, snappy, zlib and lzmA codec type