Remove .registerHelper - it has been removed from Grunt 0.4.0a

[Iristyle]

The grunt.registerHelper API has been completely removed from the 0.4.0a (devel branch) -- see issue 354 / changeset for the explanation.

An example of rewriting a task to remove registerHelper is here

Here's another look a the lint task - 0.3 to 0.4
0.4 lint.js
0.3 lint.js

[Iristyle]

Furthermore, grunt.utils has been renamed to grunt.util