Warn about accidentally deleted files in Mercurial repositories

This makes it behave the same way as with Git, and makes tests failed
with FORCE_TEST_VCS=hg.

AFAICT the original bug (#32) never affected Mercurial repositories, so
the user-visible change is merely cosmetic.

check_manifest.py

@@ -285,7 +285,7 @@ class Mercurial(VCS):
     @staticmethod
     def get_versioned_files():
         """List all files under Mercurial control in the current directory."""
-        output = run(['hg', 'status', '-ncam', '.'])
+        output = run(['hg', 'status', '-ncamd', '.'])
         return add_directories(output.splitlines())
 
 

tests.py

@@ -1192,7 +1192,8 @@ def test_bad_ideas(self):
                       sys.stderr.getvalue())
 
     def test_missing_source_files(self):
-        # XXX: fails when self._vcs is BzrHelper() or HgHelper()
+        # https://github.com/mgedmin/check-manifest/issues/32
+        # XXX: fails when self._vcs is BzrHelper()
         from check_manifest import check_manifest
         self._create_repo_with_code()
         self._add_to_vcs('missing.py')