* Adds benchmark for direct/indirect wasm function calls
* Store the benchmark function pointer in a `Cell`
* Add some documentation
* Make function implementations exchangeable
* Add parachain stub
* Add macro for registering the `validate_block` function
* Make all functions replace-able by unimplemented
* Some more refactoring
* Adds tests for executing empty parachain block
* Work on a new test with empty witness data
* Don't exchange `ext_print_*` stuff
* Some cleanup and one more function for `validate_block`
* More tests and more functions
* Fixes after merging master
* Use `parity-codec` `derive` feature
* CHange implementation of `wasm-nice-panic-message`
* Move `parachain` stuff to cumulus
* Updated wasm files
* Integrate feedback
* Switch to `ExchangeableFunction` struct
* More fixes
* Switch to Cell and panic on multiple replaces
* Increase `impl_version`
* Fix shifting
* Make the API more verbose of `ExchangeableFunction`
* Increase `impl_version`
* Add simple benchmark for the runtime api
* Make the executor support native calls
* Some documentation
* Hide behind `feature = "std"`
* Rework the native calls
* Make all tests compile again
* Make every parameter using the Block serialized/deserialized in the native call
* Forward `UnwindSafe` requirement
* Remove debug stuff
* Add some documentation
* Fixes warnings
* Fixes errors after master rebase
* Fixes compilation after master rebase
* Fixes compilation after rebase
Bastian Köcher