Long overdue fixes to the Polaroid cameras.

- Mobs lying down are captured properly.
- Hair and other coloring is captured properly.
- Darkness is now captured, though other area effects are not.
- Object layering is much more accurate, though still not perfect.
- Objects that were missing should now be visible.
- Objects that should not have been visible should now be gone.
- Some objects (like blood trails) are not yet captured properly.

I'd like to encourage players to snap pictographs of anything they set their eyes on, and find anything else that may be captured incorrectly.

Issues fixed: #131 #1359
Not sure if fixed: #259 (Can someone check?)
Does not fix interaction with MULEs, or blood trails.

Screenshots of screenshots:
[Shading, stacked items, fallen monkey.](https://f.cloud.github.com/assets/1637936/2191440/1994ed94-9848-11e3-9657-b0699f06ad47.png)
[Debrained corpse.](https://f.cloud.github.com/assets/1637936/2191441/1b21d5be-9848-11e3-8570-057292592e5a.png)