caching flag
debug flag
merged script, no  controller in :production
Merge branch 'release/v1.2.2' into development
* added cache_on env var, (defaults to 'true' only in `:production`)
* added `dotenv` gem (to `:development` and `:test`) to easily set env vars
* fixed imagesLoaded script to fire after each image even on ajax-loaded pages
* moved `/flush` route into new `:dev` controller
* added `/env` and `pry` methods (except :production)