* [ci] Check format of UI tests as well

* [lang] Apply our formatting guidelines to UI tests

* [ci] Make Gitlab happy

* [ci] Remove superfluous space

* [ci] Output rustfmt version

* [ci] Tune rustfmt params

* Remove todo's

* Migrate erc721 ui test contract to recent example contract

* Remove --version command used to debug

* Apply cargo fmt

* .gitlab-ci.yml formatting

* Add main fn

* Remove todo from stderr expect

* Adapt fixtures

* Revert "Adapt fixtures"

This reverts commit 174c012e.

* Adapt fixtures

* [lang] Improve invalid selector message

* [lang] Improve span

* [lang] Return syn::Error instead of panicking

* Make clippy happy

* [lang] Reduce code dup with non_hex_err

* [lang] Rename fn

* [lang] Fix err functions

* [lang] Add comments

* [lang] Remove unnecessary lifetime

* [env] remove unnecessary copy of no longer used mod.rs

* [env, lang] make crates compile again under newest Rust nightly

* [env] on-chain: enhance ScopedBuffer

Add append_encoded and take_appended methods.

* [env] remove old Topics trait

* [env] add new Topics infrastructure

* [env] implement new Topics infrastructure for on/off chain environments

* [env] remove dummy event

* [env] make env::topics::state mod externally accessible

It stays hidden in docs.

* [lang/codegen] generate proper Topics impls for ink! events

* [env] apply rustfmt

* [lang/codegen] fix codegen for events without topics

* [lang/macro] fix UI test

* [env] off-chain: clean-up slightly

* [examples] ERC-20: improve tests for event topics

* [env] remove commented-out line

* [lang/codegen] include event signature into topics

This is the same as it is done for non-anonymous Solidity events.
The signature of an ink! event is: ContractName::EventName.
E.g. for ERC-20's Transfer event it is: Erc20::Transfer

* [examples] ERC-20: adjust test for changes with event topics

* [lang/ir] add support for anonymous events

* [lang/codegen] add codegen for anonymous events

* [lang/ir] apply rustfmt

* [lang/macro] comment out failing unit test

Fails due to rustc version mismatch and some recent error display change.

* [examples] apply rustfmt

* [*] move all ink! crates into crates/ directory

* [ci] adjust .gitab-ci.yml to crates/ directory

* [ci] fix GitLab .gitlab-ci.yml (attempt #2)

* [ci] forgot some lines in attempt #2

* [examples] fix example smart contracts

They need to readjust their paths for the crates/ directory.