make warning message look like git status output

doc/make.py

@@ -258,7 +258,7 @@ def all():
         with open(link, 'r') as content:
             delete = target == content.read()
         if delete:
-            symlink_warnings.append('unsupported symlink {} removed'.format(link))
+            symlink_warnings.append('deleted:  doc/{}'.format(link))
             os.unlink(link)
         else:
             raise RuntimeError("doc/{} should be a directory or symlink -- it isn't")