[Add] library log-1.0
[Modified]change the visibility of the function start
[Add]SendFinish
     SendProgressUpdate
[Delete]SendFinish
     SendProgressUpdate
[Add] Debug
[Add] setFinishTime when the mode is MODE_DEFAULT
[Add] add DownloadListener to DownloadTask
[Add] add message to DownloadException
[Add] add get() and set() of the listener  to DownloadTask
[Add] remove DownloadListener form some methods
[Add]   case HttpURLConnection.HTTP_PARTIAL:
[Add] log in the MainActivity for test
[Fix]  get the wrong size of the file while the range is no zero.
[Modified] get the Accept-Ranges and Transfer-Encoding when the response code is 200 or 206
[Fixed] set range to 0 when the Accept-Ranges is none,but not bytes
[Add]  auto get filename
[Delete] STATUS_PAUSED
[Update]lib  com.github.snowdream.android.util:log:1.0.1
[Remove] message  to deatilmessage
[Update] copyright