Migrate Google-Docs-based documetation into a Markdown-based README.md. Auto-TOC generated with http://doctoc.herokuapp.com/
Merge pull request #85 from cgruber/migrateautovaluedocs

Migrate Google-Docs-based documetation into a Markdown-based README.md.
In AutoValueProcessor, accumulate template variables as fields in a class rather than just filling in entries in a Map. This gives extra type checking and provides a place to document the meaning of each variable.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=63310701
Fix AutoValue user guide address.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=63685081
Move snapshot dependencies to proper release versions.