Preset: Grunt

Fixes #742

Depends on: https://github.com/jscs-dev/node-jscs/pull/749
Hey @stephanebachelier. Thanks for the info. Would you like the grunt preset to enforce a 120 line width? Those other cases would have to be corrected or [disabled](https://github.com/jscs-dev/node-jscs#error-suppression).

The alternative is to allow exceptions to the line width rule for concatenated strings and comments. That seems like it would be best as a plugin rule.