[formrenderers] if a tag object gets there, it blows (closes #2410462)
- cwtags monkeypatches cubicweb's UStringIO's .write and .getvalue methods
- but it cannot monkeypatch list.append ...
debian/tmp/usr/lib/PY_VERSION/site-packages/cubicweb/web usr/lib/PY_VERSION/site-packages/cubicweb
debian/tmp/usr/share/cubicweb/cubes/shared/data usr/share/cubicweb/cubes/shared
debian/tmp/usr/share/cubicweb/cubes/shared/wdoc usr/share/cubicweb/cubes/shared