Add a grunt checker for jshint, jscs, csslint, and banana and pass them

There was a pre-existing jshint config (.jshintrc) file that this upgrades based
on the equivalent files for VisualEditor and OOjs UI.

Change-Id: I3ecb0e65cc7ff090b7457be895917fbd8b8afd18
(cherry picked from commit 64a39ae4607b9a3fe5ec4683772596e1b5deafe4)