* client: allow reverting blocks past finality

* client: fix leaves reversion

* client: extend docs on revert

* client: add comment on leaves revert

Good night sweet prince

Previously one would create a sender and receiver channel pair, pass the
sender to the `build_network_future` through the service builder and
funnel network events returned from polling the network service into the
sender to be consumed by the authority discovery module owning the
receiver.

With recent changes it is now possible to register an `event_stream`
with the network service directly, thus one does not need to make the
detour through the `build_network_future`.

* client/authority-discovery: Limit number of connections to authorities

Instead of connecting to all sentry nodes of all authorities, with this
patch the authority discovery module does the following:

- Choose one sentry node per authority at random.

- Choose MAX_NUM_AUTHORITY_CONN out of the above at random.

The module uses randomness to prevent hot spots, e.g. all nodes trying
to connect to a single node. If the authority discovery module would
choose the nodes to connect to at random on each new address that it
learns of, the node would go through a lot of connection churn.  Instead
it creates a random seed at start up and uses this seed for its RNG on
each update cycle.

* client/authority-discovery: Extract address cache into own module

* client/authority-discovery/src/addr_cache: Add basic unit tests

* client/authority-discovery: Replace unwrap with expect on [u8] cmp

* .maintain/sentry-node/docker-compose.yml: Prefix endpoint flags

* client/authority-discovery/src/addr_cache: Use sort_unstable and cmp

* client/authority-discovery: Use BTreeMap in addr_cache for sorted iter

To reduce connection churn it is preferrable to have `get_subset` of the
`addr_cache` to return the same result on repeated calls. `get_subset`
iterates a map. To make the process of iteration deterministic, use a
`BTreeMap` instead of a `HashMap`.

* triggers srml-contracts-waterfall ci

* only nightly and merges

* substrate does not use tager cache so far

* Fix period of offchain transactions.

* Calculate period dynamically.

* Convert to u64.

Co-authored-by: Bastian Köcher <[email protected]>

* update libp2p

* update toml files also

* Insert key via node RPC.

* somewhat address the reivew

* Update bin/utils/subkey/src/rpc.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Update bin/utils/subkey/src/rpc.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Update bin/utils/subkey/src/main.rs

Co-Authored-By: Bastian Köcher <[email protected]>

Co-authored-by: Bastian Köcher <[email protected]>

* Don't use compressed ecdsa public key in verify

* Make `ECDSA` public support compressed

* Make it a proper `expect` message

Changes in https://github.com/paritytech/substrate/pull/4462 required a
metadata version increment that was forgotten.

* Make wasm-builder remove invalid members

Wasm-builder now removes members that point to packages that do not
exist anymore or that were renamed. Up to now, the build would fail and
required manual fixing.

* Fixes build

* Fix cli for structopt 0.3.7 and pin to that version

This is just some hotfix to make everything compile. In the future it
will require another pr to not depend on internals of StructOpt, but
that will probably also require some additions to StructOpt itself. To
not break the code again with another StructOpt, this also pins the
StructOpt version.

* Fix benches

* Fix for fix

* build node job is separated from build substrate; less dupes, cleanup

* it's not effective yet to split these jobs

* Support loading the URI from a file in subkey

* Fix tests

* initial block import handler

* fix node template

* fix error message

* fix error message again

* final fixes

* fix node template again

* Implement local_peer_id for gossip

* refactor local_peer_id

* fix

* reset gossip

* Update tests.rs

* fix ci

* fix review

* fix Cargo.lock

* fix Cargo.lock

* Clean imports in wasmi_execution

* Replace `interpret_runtime_api_result` with `pointer_and_len_from_u64`.

* Extract sc-executor-common crate

* Extract `sc-executor-wasmi` into its own crate

* Extract `sc-executor-wasmtime` into its own crate.

* Add missing headers.

* Clean and docs

* Docs for sc-executor-wasmi

* Expand a comment about sandboxing

* Fix assert_matches

* Rename (un)pack_ptr_and_len and move them into util module

* Remove wasmtime errors in sc-executor-common

* Fix transaction replacements.

* Test.

* Fix typo.

* Update client/transaction-pool/graph/src/ready.rs

Co-Authored-By: Bastian Köcher <[email protected]>

Co-authored-by: Bastian Köcher <[email protected]>

* Migrate election-phragmen

* Migrate elections

* Migrate contracts module

* Update authorship module

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <[email protected]>

* ci: increase git cloning depth to 100

* check_runtime: verify shallow git clones to contain origin/master

* check_runtime: fetch master branch