added test cases with two initial audio and video streams
Checkpoing
Merge pull request #11 from adamroach/multistream

Checkpoing
Merge pull request #10 from nils-ohlmeier/multistream

added test cases with two initial audio and video streams
Virtual is my friend
Merge branch 'multistream' of https://github.com/adamroach/gecko-dev into sdp_stub

Conflicts:
	media/webrtc/signaling/src/sdp/Sdp.h
	media/webrtc/signaling/src/sdp/SdpAttribute.h
	media/webrtc/signaling/src/sdp/SdpEnum.h
	media/webrtc/signaling/src/sdp/SdpMediaSection.h