#26908 Added flame clip updater to nuke multi publish

This adds a new secondary task for the nuke publish which updates the clip xml for the current shot:

![screen shot 2014-12-12 at 16 27 41](https://cloud.githubusercontent.com/assets/337710/5416931/75acf72e-822c-11e4-9e83-252067670d8b.png)

When the flame box is ticked, items will appear in the version dropdown for that clip in flame:
![screen shot 2014-12-12 at 16 33 35](https://cloud.githubusercontent.com/assets/337710/5416941/9504469a-822c-11e4-853e-d71bcd4e4e52.png)



good point. It's not a publish area per se, but i'll add a comment to guide future readers of the code.