replace painter::draw() iterator argument by specs::RunArg

[theor]

by letting it fetch whatever it needs, it is now possible to have multiple visual component types or to use resources.

I had the issue in a toy project - I need multiple components to be able to draw (position, mesh and a couple of resources (shadercache, meshcache, ...). I think this gives back the flexibility of specs without adding any boilerplate you would not see in the rest of the project. What do you think ?

[kvark]

Oh man, my notifications are screwed up, sorry for missing it!