* [x] Introduce oscoin as another name for "open source coin" * [x] Reference TrustRank * [x] Remove mentions of pledging/stake * [x] Explain the intuition on why the structure of os projects is different than the web, and why that leads us to add contributors to the graph. * [x] Mention vesting on reward tokens * [x] Clear up confusion around term "bidirectional" in 3.4 * [x] Talk about checkpointing incentive? (Receive more Osrank from contributors) * [x] Talk in more detail about why we're using a blockchain. (Governance, minting) * [x] Mention concerns about PoW at scale * [x] Acknowledge and address issue with false dependencies and omissions in Future Work section * [x] Improve background section's language around OSS * [x] Mention the primary focus on libraries and "upstream" dependencies * [x] Talk about "Free Software" * [ ] Write conclusion