Reintroduce lint:html cake task
Add linting for coffeescript files

The settings doesn't per default include checks for trailing whitespace
nor long lines, since that causes over 500 errors.
Add coffeelint as a dependency and use that local version for linting
Merge pull request #587 from saebekassebil/cake

Reintroduce linting tasks in Cakefile for both HTML and CoffeeScript