LIP-6: More on specifications, corrections/clarifications through the text

[valerini]

• Adding more clarifications
• Better flow for the document
• Fix the notations (to use capital terms everywhere)
• Add a picture to lift confusion
• Adding more concrete things on specifications

[davidiw]

This is sooooo awesome. At this point, I'd like to start looking at deltas on top of this instead of just revising the core content.