Upgrade to `pipes-4.0.0`

As part of the transition to `pipes-4.0.0` I'm fixing downstream libraries that depend on `pipes`.  This pull requests fixes `hist-pl` to compile against the latest `pipes` on Hackage.

Do not merge this pull request until you check that it compiles.  I was able to verify that the changes to `hist-pl/lexicon` compiled correctly, but not the changes to the main `hist-pl`, because I didn't have the `morpheusz` library.  However, I'm reasonably sure that it should compile because the necessary change was very small.