Release/0.5.2rc2

Takes @egonina 's work and ads the final few bits to get green tests. Given its for the forth coming scalding release it seems good to just merge into develop with changes this much here.

@johnynek changes here are all around the scalding platform, could you take a look? Thanks!
I'm confused as to how this can possibly work then. I bet the manifest being inferred in Nothing, and so this thing is going to break at runtime, but no one is using it.