* fix lock type in doGet
* add volatile to frame and contentType
* add comments
* close accepted connection soon if
UTF8StringReceiver.ListenCompletionListener.accept returns null
* add RawMJPEGReceiver to receive a bare MJPEG byte stream.
* add statistics counter and output it to log
* add remote address to log messages
* fix log level
* add statistics counter and output it to log
* change log level
* modify boudary byte pattern to avoid that it fails to split some
 multipart stream

Some multipart MJPEG stream forgets to insert a CRLF before boundary
string
* add splittig jpeg frame code
* remove wastful memory copy
* fix a problem that MjpegHTTPReader cannot found a JPEG frame from
multipart stream

The loop to search a multipart body pass throuh a delimiter between
header and body, CRLFCRLF, couse of lack of a break.
* remove debug print
* strip pure JPEG frames by detecting SOI and EOI

Merge branch 'stripJPEGframe' into pre_master