Backports for stable 2.1.7 (#9975)

* version: bump stable to 2.1.7

* Adjust requests costs for light client (#9925)

* PIP Table Cost relative to average peers instead of max peers

* Add tracing in PIP new_cost_table

* Update stat peer_count

* Use number of leeching peers for Light serve costs

* Fix test::light_params_load_share_depends_on_max_peers (wrong type)

* Remove (now) useless test

* Remove `load_share` from LightParams.Config
Prevent div. by 0

* Add LEECHER_COUNT_FACTOR

* PR Grumble: u64 to u32 for f64 casting

* Prevent u32 overflow for avg_peer_count

* Add tests for LightSync::Statistics

* Fix empty steps (#9939)

* Don't send empty step twice or empty step then block.

* Perform basic validation of locally sealed blocks.

* Don't include empty step twice.

* prevent silent errors in daemon mode, closes #9367 (#9946)

* Fix light client informant while syncing (#9932)

* Add `is_idle` to LightSync to check importing status

* Use SyncStateWrapper to make sure is_idle gets updates

* Update is_major_import to use verified queue size as well

* Add comment for `is_idle`

* Add Debug to `SyncStateWrapper`

* `fn get` -> `fn into_inner`

*  ci: rearrange pipeline by logic (#9970)

* ci: rearrange pipeline by logic

* ci: rename docs script

* Add readiness check for docker container (#9804)

* Update Dockerfile

Since parity is built for "mission critical use", I thought other operators may see the need for this.

Adding the `curl` and `jq` commands allows for an extremely simple health check to be usable in container orchestrators.

For example. Here is a health check for a parity docker container running in Kubernetes.

This can be setup as a readiness Probe that would prevent clustered nodes that aren't ready from serving traffic.

```bash
#!/bin/bash

ETH_SYNCING=$(curl -X POST --data '{"jsonrpc":"2.0","method":"eth_syncing","params":[],"id":1}' http://localhost:8545 -H 'Content-Type: application/json')
RESULT=$(echo "$ETH_SYNCING | jq -r .result)

if [ "$RESULT" == "false" ]; then
  echo "Parity is ready to start accepting traffic"
  exit 0
else
  echo "Parity is still syncing the blockchain"
  exit 1
fi
```

* add sync check script

* Fix docker script (#9854)


* Dockerfile: change source path of the newly added check_sync.sh (#9869)

* Do not use the home directory as the working dir in docker (#9834)

* Do not create a home directory.

* Re-add -m flag

* fix docker build (#9971)

* bump smallvec to 0.6 in ethcore-light, ethstore and whisper (#9588)

* bump smallvec to 0.6 in ethcore-light, ethstore and whisper

* bump transaction-pool

* Fix test.

* patch cargo to use tokio-proto from git repo

this makes sure we no longer depend on smallvec 0.2.1 which is
affected by https://github.com/servo/rust-smallvec/issues/96

* use patched version of untrusted 0.5.1

* ci: allow audit to fail

parity/informant.rs

@@ -184,7 +184,7 @@ impl InformantData for LightNodeInformantData {
 	fn executes_transactions(&self) -> bool { false }
 
 	fn is_major_importing(&self) -> bool {
-		self.sync.is_major_importing_no_sync()
+		self.sync.is_major_importing()
 	}
 
 	fn report(&self) -> Report {

parity/run.rs

@@ -396,11 +396,6 @@ fn execute_impl<Cr, Rr>(cmd: RunCmd, logger: Arc<RotatingLogger>, on_client_rq:
 	// create dirs used by parity
 	cmd.dirs.create_dirs(cmd.acc_conf.unlocked_accounts.len() == 0, cmd.secretstore_conf.enabled)?;
 
-	// run in daemon mode
-	if let Some(pid_file) = cmd.daemon {
-		daemonize(pid_file)?;
-	}
-
 	//print out running parity environment
 	print_running_environment(&spec.data_dir, &cmd.dirs, &db_dirs);
 
@@ -800,6 +795,12 @@ fn execute_impl<Cr, Rr>(cmd: RunCmd, logger: Arc<RotatingLogger>, on_client_rq:
 	client.set_exit_handler(on_client_rq);
 	updater.set_exit_handler(on_updater_rq);
 
+	// run in daemon mode
+	if let Some(pid_file) = cmd.daemon {
+		info!("Running as a daemon process!");
+		daemonize(pid_file)?;
+	}
+
 	Ok(RunningClient {
 		inner: RunningClientInner::Full {
 			rpc: rpc_direct,