This commit continues previous work and also #708 by removing the need to use `HostRef<Module>` in the API of the `wasmtime` crate. The API changes performed here are: * The `Module` type is now itself internally reference counted. * The `Module::store` function now returns the `Store` that was used to create a `Module` * Documentation for `Module` and its methods have been expanded.
wasmtime-rust-macro
This is the actual definition of the #[wasmtime] macro, but it's intended that
this crate isn't used directly but rather the wasmtime-rust crate is used
instead.