including refactoring, disabling sourcepos for pipelines that
don't need it, and minimizing spec changes by disabling
sourcepos when not testing for it explicitly.
This adds 'data-sourcepos' to tags, indicating which
line of markdown it came from. Sets the stage for
intelligently manipulating specific lines of markdown.
Updates specs to use new rails5 format.
The old format:
`get :show, { some: params }, { some: headers }`
The new format:
`get :show, params: { some: params }, headers: { some: headers }`