Slightly reorganize clean

Makes it so that impls are next to their struct
Extract crate name and attributes

Crate name extraction is currently broken; it needs an explicit
 #[link(name="foo")]. I couldn't figure out how rustc infers crate name... I
think it just looks at the basename and strips the extension but I'm not
positive.
Generate module trees rather than a flat namespace
Update readme with overview
Clean docblock bodies of * and // artifacts
rustpkg tests awareness
Merge branch 'working' of https://github.com/jedestep/rustdoc_ng into working

Conflicts:
	clean.rs
	doctree.rs
	jsonify.rs
	main.rs
	visit.rs