OwrMediaRenderer: fix refcount bug in owr_media_renderer_set_source
sdp: Allow a=rtcp address to be optional

In accordance with RFC 3605
bridge: Don't assume mdesc.rtcp exists when checking mdesc.rtcp.mux
domutils: Use the expected variable name
webrtc_js: Avoid assigning the same property twice
peerhandler: Set the TURN server transport type from the iceServer URL

In accordance with RFC 7065
Add test utilities

Run ./out/<platform>/bin/test-self-view after building to run a simple
audio/video capture and output test.

Run ./out/<platform>/bin/test-send-receive after building to run a test
with one sender and one receiver in the same application.
Update scripts

Various build fixes.