• Optimize multipart content provider to coalesce small writes and reduce TCP packet fragmentation by
  @yhirose in #2410
• Add set_socket_opt function and corresponding test for TCP_NODELAY option by @yhirose in
  #2411
• Implement request body consumption and reject invalid Content-Length with Transfer-Encoding to prevent
  request smuggling by @yhirose
• Fixed warnings by @yhirose