fix read full package bug
don't waitting for empty packet
edit README
make the import standardization
Merge pull request #2 from astaxie/master

make the import standardization
standardization
fix bad WaitGroup use case
close the session when write packet returns error
add license
Update README

There is no ```server.Start()``` function defined. Simply call ```server.Handle()``` function will launch the server.
fix server_test data race bug
Merge pull request #3 from reterVision/patch-1

Update README
Merge pull request #4 from yourihua/master

fix server_test data race bug
edit README;
Merge branch 'master' of https://github.com/funny/link
improve session API
public the send packet API.
make session always need to started by manual
refactor broadcast API
refactor sync.Mutext usage and remove unused field