Fix #3056, avoid CMS.Plugin name clashes with render_model_icon and render_model_block
Fix wrong dict name and python 3 compatibility
Test added
Debug leftover
Fix python 2.6 and django 1.4 issues in tests
Merge pull request #3057 from johnraz/Issue3056

Fix #3056, avoid CMS.Plugin name clashes with render_model_icon and...