Merge branch 'devel-2.7'

* devel-2.7:
  Update required pylint version
  Constants.hs.in: improve Haddock markup in the template
  convert-constants: generate better Haddock markup
  Expand Haddock to run over test files as well

Conflicts:
        Makefile.am (curl changes and new hs directories)

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>