First round deleting the component sets.

src/data/mod.rs

@@ -2,10 +2,8 @@
 
 pub use self::arena::{Arena, Index};
 pub use self::coarena::Coarena;
-pub use self::component_set::{BundleSet, ComponentSet, ComponentSetMut, ComponentSetOption};
 
 pub mod arena;
 mod coarena;
-mod component_set;
 pub(crate) mod graph;
 pub mod pubsub;