Move all the contact manifold computations out of Rapier.

src/data/mod.rs

@@ -1,11 +1,9 @@
 //! Data structures modified with guaranteed deterministic behavior after deserialization.
 
 pub use self::coarena::Coarena;
-pub use self::maybe_serializable_data::MaybeSerializableData;
+pub use eagl::utils::MaybeSerializableData;
 
 pub mod arena;
 mod coarena;
 pub(crate) mod graph;
-pub(crate) mod hashmap;
-mod maybe_serializable_data;
 pub mod pubsub;