Blender Git Loki

Muliview: Minor UI-tweaks

* Don't grey multiview options in file browser and in Node Editor Properties out if multi-view is disabled, hide them completely (I think greying out single buttons is fine, but in case of entire blocks we should just hide to save space)
* Move multiview settings in Node Editor Properties above alpha settings to prevent the alpha buttons from appearing above multiview settings if multiview is enabled and Stereo 3D format is chosen (making them appear below is much nicer)