* node: add sentry mode flag

* cli: extend docs on validator and sentry modes

* service: add missing field in test Configuration

* node: Display instead of Debug when printing node role

* grandpa: fix handling of catch-up requests

* grandpa: fix tests

* grandpa: add test for catch-up handling when observer disabled

* grandpa: extend doc comment

* grandpa: rename existing catch up test

* Introduce new option "always force new era".

* Take appropriate action, even for small offences.

- Deselect the offender in all circumstances
- Ensure that deselection forces a new era
- Ensure that forcing a new era works with the always-forcing.

* Bump runtime

* Initial sotrage migration

* Fix some deps

* test added

* another dep removed

* Update srml/elections-phragmen/src/lib.rs

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

* Apply suggestions from code review

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

* a bit nicer

* Change DefaultMaxDepth from 1024 to 32

* Switch sr-arithmetic benchmarking to criterion

* Update core/sr-arithmetic/Cargo.toml

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

* Update core/sr-arithmetic/benches/bench.rs

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

* Test on variable limb lengths

* Change license

* Rework division

* Remove footgun around session keys/handlers

- `OpaqueKeys` now has an associated type `KeyTypeIdProviders`. This can
be used in the runtime as input for `SessionHandler` from the session
trait.
- `impl_opaque_keys` now works with modules and extracts the `KeyTypeId`
from the module directly.
- Added some checks to the `session` storage initialization that checks
that the `SessionHandler` and `Keys` use the same number of keys and
that the order is equal.

* Update core/sr-primitives/src/traits.rs