[add-external-socketio-client] add both minimal and normal socketio client lib release v0.9.16 from https://github.com/LearnBoost/socket.io-client

-update moduleConfig to include in external as well as "socketio" module
-test can be found in cocos2d-js repo, Extensions -> Network -> SocketIOTest

Signed-off-by: Chris Hannon <himynameschris@gmail.com>
Merge pull request #1713 from hannon235/add-external-socketio-client

[add-external-socketio-client] add both minimal and normal socketio clie...