Rediscuss argument IDs
With arguments recrawling, using the timestamp of acquisition in the idea is not good if we want to provide a page for each argument. This way, links to such pages become dead when we re-index (about once per week?) in the future.
Hashing the content (premise + conclusion?) might be a better idea (in addition to the URL has). This breaks when arguments get updated. But we could check for arguments that we would loose for any URL and keep them around if we want.