Update version to 2.0.0.0, file/nuget version 2.0.1. Skipping 2.0.0 due to incorrect version of the development nuget feed.
Update license year
Remove duplicate import, and fix partial builds on mac
Update nuget and assembly descriptions
Don't publish Mac64 - it is only usable with a custom compiled mono at this point.
Merge branch 'release/2.0' into develop