Game Binding: Let me select a MixPlay project shared with me

[gostay]

The Unreal mixer plugin lets me choose a Game Version Id to use in my project. When I’ve got the “From Mixer User” button selected, the list of projects includes only projects I created myself.
That list should include all projects shared with me.

Use case: several developers working on the same experience. Some working on the game client side of things, and some working on the interactive controls. They shouldn’t all have to have their own copy of the mixplay project, especially if they’re only working on the game client experience.

Note: It’s possible to manually enter a Version Id and work around this problem, but it’s shaky and confusing (see bug #43) : I have to be in “manual” mode, which then hides my login button, and I certainly need to be logged in. And I am by default shown a mixed manual/from-user display that has a project name of mine but the “unknown” version id I entered manually. It’d be better if I could just pick a shared project and have everything work as if it were my project.