* due to sprockets digest method, we are forced to use a workaround to allow
"precompilation" of .dart files, see [non-stupid-digest-assets](https://github.com/alexspeller/non-stupid-digest-assets)
and [Inability to compile nondigest and digest assets breaks compatibility with bad gems #49](rails/sprockets-rails#49)
it is optionally (and automatically) available by adding `gem 'non-stupid-digest-assets', '>= 1.1', github: 'm0gg/non-stupid-digest-assets'
` to your Gemfile
* added dart_app.js to precompile list
* faced an issue with UglifyJs stackoverflowing with too large dart2js files