This was only halfways supported, as the download module does not
have an image_url function. So for this, it just uses the url function,
which is just the original URL passed into the download function.
Additionally, it adds support to grab the largest available image,
which it does by using the file_url function of the downloads module.
- Fixes image_url parameter
- Adds file_url parameter
Previously the search form on the /iqdb_queries page submitted directly
to the iqdb service (karasuma.donmai.us), which redirected back to
Danbooru with the search results.
This was different than API requests, which submitted to
/iqdb_queries.json which proxied the call to iqdb through Danbooru.
Because of this, searches on the /iqdb_queries page had different
behavior than API requests. Things like filesize limits and referrer
spoofing were handled differently.
Now searches on the /iqdb_queries page submit directly to Danbooru. This
is simpler and it means that API requests and HTML requests have the
same behavior.
* Change cutoffs on upload page to max 5 results, min. 20% similarity.
* Change cutoffs on standalone /iqdb_queries page to max 20 results, min. 0% similarity.
* /iqdb_queries.json: add `limit` and `similarity` params to change default cutoffs.
* Remove file_path_for, cropped_file_url (dead code)
* Remove complete_preview_file_url (preview_file_url now returns absolute links)
* Remove `file_name` (only used for Download link in sidebar)
