Move entire app into its own package, as suggested by flask docs

See http://flask.pocoo.org/docs/patterns/packages/
Add private gist support implemented by @julen

https://github.com/julen/gistio/commit/cba7fd3a8fc038d29f29da48b1ba5d51eb9a5b81
removed tracking

Signed-off-by: Kenneth Nordahl <kenneth@nordahl.me>
Fix home layout issue introduced by 410ee59 floats
More tracking removal (mixpanel)
Enable fenced codeblocks and highlighting for github markdown compat
Add support for embedding gists