This changes the Grunt script to automatically pull the locations of the
NPM versions of the Almond loader and jQuery mousewheel plugin. This
means we no longer need to include these vendor files in our repository,
as the builds will automatically pull from the existing NPM files.
jQuery.mousewheel will allow us to prevent the dropdown from
automatically closing when the user scrolls to the end of the list.
It is automatically bundled in the full versions of Select2 and
we don't require that it is included in order for Select2 to work.
jQuery.mousewheel was taken directly from the source repository
using the commit at
cc2c5d73ae