This allows users to run multiple servers on different ports for testing.
Only done for examples that actually take arguments and hence are capable of
outputting different streams for each instance on each port.
https://bugzilla.gnome.org/show_bug.cgi?id=742115
Added various other test server examples
Move the SDP message generation to a separate helper.
Refactor common code for finding the session.
Add content-base for realplayer compatibility
Clean up request uris before processing for better vlc compatibility.
Move prerolling and pipeline construction to the RTSPMedia object.
Use multiudpsink for future pipeline reuse.
