Add penalties, problem of delegation to whitepaper

Change document formatting style
replace \space with ~
Rename Introduction - Nontechnical to Introduction
Rename Introduction - Technical to Overview
Add penalties to the Concensus Blockchains section
Add penalties to Proof of Access  section
Discuss problem of delegation
Merge branch 'master' of github.com:Siacoin/Sia
Fixed newcommand whitespace issues
grammar and concept reorganization
discuss dishonest blockchains
addressed PR comments
Merge branch 'master' of github.com:Siacoin/Sia
Merge branch 'master' of github.com:Siacoin/Sia
Merge pull request #46 from DavidVorick/master

Whitespace, penalties, dishonest blockchains