mqtt-client C++11

I wrote this client just for studying:

• New features of C++11
• Nonblocking socket
• OpenSSL
• Understand clearly about MQTT protocol

##Feature

• Support subscribing, publishing, authentication, will messages, keep alive pings and all 3 QoS levels
• Support security connection

##Building

On Linux:

• cd mqtt-client
• cd src
• cd MQTT
• make
• make run

On windows:

• Open visual studio
• Link project to OpenSSL include and library folder
• Build

##Usage

• Edit some code on main.cpp as you want

##Limited

• Don't support retransmit for QoS1 and QoS2

####Feel free to contribute to the project in any way you like!

####If you find out some bad code (code not clean). Please anounce to me because the purpose that I create this project just for studying.