remove all exceptions

cleanup unitest for co/json

remove all exceptions

remove all exceptions

update documents

Merge pull request idealvin#120 from idealvin/dev

update vs project

Merge pull request idealvin#113 from idealvin/dev

update docs

Merge pull request idealvin#96 from idealvin/dev

merge from dev

Merge pull request idealvin#95 from idealvin/dev

fix assert bug in disconnect() of tcp::Client

Merge pull request idealvin#73 from idealvin/dev

update readme