Robots and humans peacefully coexist

Added disallows to robots.txt, preventing access to /app, /content,
/plugins, and /templates. The /js and /css are allowed to be indexed,
as Google and other bots sometimes need this Created a template for
humans.txt
Merge branch 'robots-and-humans'
Fix for the Safari blank-page bug

Prevent Stacey from sending 304 headers to browsers that identify with
the Safari USER_AGENT.
Merge branch 'safari-caching-304'