Gaps + Explicit gaps on both sides

[Inviz]

When using explicit variables gaps, the parser greedily captures some VFL stuff between them when using regular - gap.

.block{
  @v |-^[inner-gap-top]-(.avatar)-(.html)-(.source)-^[inner-gap-bottom]-| gap(v-gap);
}

yields some ccss like:

 .avatar[bottom] + (.html)~(.source)-^[inner-gap-bottom] == ::this[bottom]

[paulyoung]

We should add a spec for this.

[paulyoung]

I wonder if ^inner-gap-top works vs ^[inner-gap-top].