Partially revert D3001

Authored by dfeuer on Jan 24 2017, 2:59 PM.

Description

Partially revert D3001

D3001 accidentally changed the meaning of containsSpan. Revert
that change.

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D3015

Details