Merge branch 'master' of https://github.com/socketio/socket.io-client…

…-cpp

add boolean message type, fix crash of a synchronization bug

breaking change of ack callback, windows compile fix for PR

fix wild reconnect after too many times

Merge remote-tracking branch 'origin/tls'

fix console demo compile issue in VS2012SP4

fix link error of sio::event accessors

unify use of 'std' prefix

add test cases,format code

reorg readme