* add MJPEG over HTTP reader and servlet

MjpegServlet is for embedded Jetty
* fix MJPEG multipart structure

add CRLF on the end of frame data.
fix delimiter string.
* add debug messages
* improve memory reusing
* add test and sample code of MjpegServlet
* support multiple viewer connections at same time
* remove obsolute code
* add license
* change character code of README.md to UTF-8
* update slf4j-SimpleLogger binding to adapt slf4j 1.7.5
* fix that MjpegHTTPReader does not stop before MJPEG server stopped
* add Socket read timeout
* add UTF8StringReceiver
* close sockets when UTF8StringReceiver stopped
* UTF8StringReceiver : fix exception when stop() is called if start() 
 is not called beforehand
* add comment
* add ImageServlert
* add WSImageServlet
Merge branch 'master' into pre_master
* update HttpClient 4.1.2 to 4.3.4