Log Message:
Update to aria2-0.15.3.  Changes:

  Added Turkish translation. Updated German and Russian translations.

  If an error occurred with a URI, remove identical URI from remaining
  URI list because it is likely that same error occurred in the end and it
  is waste of time.

  Added -lrt to LIBCARES_LIBS if -lrt is needed to link program with
  -lcares.

  Moved implementation to SimpleRandomizer.cc from SimpleRandomizer.h.
  Added return value of getpid() to argument of srand() to achieve more
  randomized value.

  Contact tracker frequently when the number of connections are 0 and
  download is not finished yet.

  Moved threshold values to UTPexExtensionMessage.

  Added _incoming member to Peer class and made it true if the peer
  initiated connection. Don't add those peer to UTPex message.
  If extended handshake is received, assign _incoming to false.

  Fixed infinite loop bug in FTP when SIZE command failed.

  Made files whose name ends with ".gz", ".tgz" not inflated \ 
by Content
  Encoding Decoder. Removed size threshold for turning off on the fly
  inflation because resulting file may or may not be inflated depending
  on the file size and I think it is not expected by users.
  This change fixes segmentation fault when Metalink file contains gzipped
  file and its filesize is provided.

  Fixed chunk checksum validation cannot detect trailing garbage data.
  BUG#2074141