Refactored sending of the stream header.
Refactored sending of the stream header.

Created connection_send_stream_header that reinitates the stream.

mcabber/loudmouth,mcabber/loudmouth,tuxad-loudmouth/loudmouth,tyll/loudmouth,mhallendal/loudmouth,mhallendal/loudmouth,tyll/loudmouth,tuxad-loudmouth/loudmouth