make json serializations compatible with anki: Python's json.dumps()
function doesn't escape forward slashes when serializing. Android's
org.json.JSONObject.toString() function does escape them. That means
that when we save some card templates (frequently having tags that have
a forward slash when closing) we might be breaking them.
Merge pull request #31 from iniju/v2.0.1-json-escape-fix

Fix for JSON escaping.