Fixed everything else

makefile:
* Changed lints to be correct
  * unused-variable -> unused-variables
  * dead-assignment -> unused-assignments

rust files:
* Changed fail!() calls to panic!() calls
* Changed some syntax so that slices are correct
  * i.e. in array.rs (analyze_slice(xs) -> analyze_slice(&xs))
* Namespaced enums
* Renamed `Node` to `List` in enum.rs
  * Renamed List::append() to List::prepend(), which is the actual
    operation that is taking place
* Renamed fail/fail.rs to panic/panic.rs
  * And everything that comes with that
* Changed any `{:t}`s to `{:b}`s
* `use`d std::num::Float in places that needed it
* In fmt/show.rs, changed {:.3f} to {:.3}
* Changed hash table .find() to .get()
  * Took out the parens in a string .get(), so that
    `h.get(&("string"))` becomes `h.get(&"string")`
* Completely removed smallintmap
* In json/decodable/decodable.rs, changed {:.2f} to {:.2}
* In src/file.rs, changed a comment to be under 79 characters long