add arrow images to be compatible with django-treemenus
readme-update
Merge pull request #61 from iElectric/treemenus-compatibility

add arrow images to be compatible with django-treemenus
master to 2.4.0
prepared rtl integration, see #198
updated rtl-styles, see #198
updated rtl styles, see #198
removed rtl-workarounds in base.html, see #198
minor js updates (jshint), see #197
updated rtl styles, see #198
docs update
updated rtl styles, see #198
hide parent li of counterContainer with change list actions (prevent li from creating an invisible margin)
updated rtl styles, see #198
updated rtl styles, see #198
updated rtl styles, see #198
updated rtl styles, see #198
updated rtl styles, see #198
updated rtl styles, see #198
cleaning up some rtl styles, see #198