dartium 38663 (new formula)

Added suport to install the latest stable dartium browser from
https://www.dartlang.org. The browser is used to develop dart
applications and is common installed with the dart sdk provided by
dart.rb Formula
Yes, I've just noticed this and it's unfortunate. For that reason `dart` should probably not have been included as-is. 

Generally homebrew-cask is used more for graphical applications (e.g. `.app` files) and homebrew-binary is used for precompiled binaries.

The reason we try and keep these binary-only packages out of Homebrew core is because if people want to try and use a Homebrew formula on an older OSX or Linux system then the binaries will just fail whereas a from-source formula with a binary we provide still provides a fallback for non-bottled platforms.