Include coffee-lint as an option

[diwa-zz]

It will be great if the coffee code is optionally linted with Coffee-Lint.

I don't see much point in having a separate coffee-lint plugin.

[dylex]

Note that you can already use sbt-jshint on the produced coffeescript directly using something like:

JsTaskKeys.sourceDependencies in JshintKeys.jshint += CoffeeScriptKeys.coffeescript

However you'll have to relax a few jshint options (eqnull, boss) to do so.