Treat blocks, that already downloaded, as synced

.github/CONTRIBUTING.md

@@ -24,7 +24,42 @@ Also, try to include **steps to reproduce** the issue and expand on the **actual
 
 If you would like to contribute to Parity Ethereum, please **fork it**, fix bugs or implement features, and [propose a pull request](https://github.com/paritytech/parity-ethereum/compare).
 
-Please, refer to the [Coding Guide](https://wiki.parity.io/Coding-guide) in our wiki for more details about hacking on Parity.
+### Labels & Milestones
+
+We use [labels](https://github.com/paritytech/parity-ethereum/labels) to manage PRs and issues and communicate the state of a PR. Please familiarize yourself with them. Furthermore we are organizing issues in [milestones](https://github.com/paritytech/parity-ethereum/milestones). Best way to get started is to a pick a ticket from the current milestone tagged [`easy`](https://github.com/paritytech/parity-ethereum/labels/Q2-easy%20%F0%9F%92%83) and get going, or [`mentor`](https://github.com/paritytech/parity-ethereum/labels/Q1-mentor%20%F0%9F%95%BA) and get in contact with the mentor offering their support on that larger task.
+
+### Rules
+
+There are a few basic ground-rules for contributors (including the maintainer(s) of the project):
+
+* **No pushing directly to the master branch**.
+* **All modifications** must be made in a **pull-request** to solicit feedback from other contributors.
+* Pull-requests cannot be merged before CI runs green and two reviewers have given their approval.
+* Contributors should adhere to the [Parity Ethereum Style Guide](https://wiki.parity.io/Parity-Ethereum-Style-Guide).
+
+### Recommendations
+
+* **Non-master branch names** *should* be prefixed with a short name moniker, followed by the associated Github Issue ID (if any), and a brief description of the task using the format `<GITHUB_USERNAME>-<ISSUE_ID>-<BRIEF_DESCRIPTION>` (e.g. `gavin-123-readme`). The name moniker helps people to inquiry about their unfinished work, and the GitHub Issue ID helps your future self and other developers (particularly those who are onboarding) find out about and understand the original scope of the task, and where it fits into Parity Ethereum [Projects](https://github.com/paritytech/parity-ethereum/projects).
+* **Remove stale branches periodically**
+
+### Preparing Pull Requests
+
+* If your PR does not alter any logic (e.g. comments, dependencies, docs), then it may be tagged [`insubstantial`](https://github.com/paritytech/parity-ethereum/pulls?q=is%3Aopen+is%3Apr+label%3A%22A2-insubstantial+%F0%9F%91%B6%22).
+
+* Once a PR is ready for review please add the [`pleasereview`](https://github.com/paritytech/parity-ethereum/pulls?utf8=%E2%9C%93&q=is%3Aopen+is%3Apr+label%3A%22A0-pleasereview+%F0%9F%A4%93%22+) label.
+
+### Reviewing Pull Requests*:
+
+* At least two reviewers are required to review PRs (even for PRs tagged [`insubstantial`](https://github.com/paritytech/parity-ethereum/pulls?q=is%3Aopen+is%3Apr+label%3A%22A2-insubstantial+%F0%9F%91%B6%22)).
+
+When doing a review, make sure to look for any:
+
+* Buggy behavior.
+* Undue maintenance burden.
+* Breaking with house coding style.
+* Pessimization (i.e. reduction of speed as measured in the projects benchmarks).
+* Breaking changes should be carefuly reviewed and tagged as such so they end up in the [changelog](../CHANGELOG.md).
+* Uselessness (i.e. it does not strictly add a feature or fix a known issue).
 
 ## License.