rtspconnection: Add API for sending multiple messages at once, and for having the message body consist of multiple chunks of memory
Submitted by anila
Link to original bug (#785684)
Description
An API to write messages to the connection without blocking.
This is need for the support for buffer lists in gst-rtsp-server in the tcp case.MSG_DONTWAIT flag is send to sendmsg () so that nonblocking write of messages are possible.