[#493] Fix schema so we can change private via web interface
[#493] Fix check_data_dict()
[#507] Allow the template cache to be reset
[#507] Add tests for ckan/lib/render.py
[#507] Refactoring tests, so they know less about the code

Instead of stubbing ckan.lib.render methods, I simply create a
NamedTemporaryFile, add its folder to the template path, and we're done.
Should work now, c'mon