mongo in/out use bson instead of json

because MongoId can only be parsed by bson
logging
for testing
fmt
findAll test passed
mg count
mg.inserts tested
log
config tcp nodelay for better response latency
idgen servant
progress
add context to idgen arguments
idgen finished
mongo findAndModify done
better demo
refactor id generator
debug session len
install
fmt
concurrent stress test