Fixed important security issue with yaml formatters (same as in https://www.djangoproject.com/weblog/2011/nov/01/piston-and-tastypie-security-releases/)
Fixed important security issue with yaml formatters (same as in https://www.djangoproject.com/weblog/2011/nov/01/piston-and-tastypie-security-releases/)

flosch/simpleapi,flosch/simpleapi,flosch/simpleapi