World space particles

By which I mean particles that have their geometry in the same space as other geometry. As it stands, to get pixel lighting on particles is a pretty hefty undertaking involving re-writing large parts of the lighting cginc files to account for the difference in geometry spaces.

This completely undermines the idea of ShaderLab - that of making shaders simpler and unified. It would be great if Shuriken had a checkbox to set which space particles use (as I'm assuming there's a performance gain to be had by using camera space particles). This would allow us devs to write simple surface shaders to handle custom particle rendering, instead of having to re-write the includes, and making lengthy fragment shaders, just to handle lighting and other mapping, which is virtually automated on all other geometry types.