Use standard plugin naming convention

As usual, stealing things from the less and coffeescript packages. I’m
not sure why this would possibly matter, but at least it’s consistent.
Check for array length

Since we’re always expecting an array, this commit checks the length of
the array instead of whether it’s undefined.
Remove old "result" variable

I’m not sure how the old variable got through the merge, but we don’t
want to use it.
Move comment to conditional block