ascii and self-contained options conflict

[trism]

Copying an example from https://bugs.launchpad.net/ubuntu/+source/pandoc/+bug/1024754

(Edit: see the example on the linked launchpad bug, github doesn't like it)

With the third command we still have the curly quotes instead of entities. I tracked this down to src/pandoc.hs where:

| htmlFormat && ascii ->
writerFn outputFile =<< selfcontain (toEntities result)

seems to want to do the right thing, but selfcontain removes the entities toEntities added. Flipping this around:

| htmlFormat && ascii -> do
result' <- selfcontain result
writerFn outputFile =<< return (toEntities result')

seems to work and give the desired result.