Work around bugs in GMail's standard Jingle implementation

Submitted by Will Thompson @wjt

Assigned to Telepathy bugs list

Link to original bug (#38352)

Description

Hello.

Here is a branch which works around these three issues with GMail's brand new Jingle implementation:

• it omits creator='' on contents • it names the video components video_rtp and video_rtcp • it can't upgrade/downgrade

While writing this I decided my approach to the second is not ideal: it really should only do this if we're using the gtalk p2p transport. But this works for now at least.

Version: git master