Allow multiple pending, deleted or retired aliases/implications for the
same tag.
This is so that deleted or retired aliases can be resubmitted as new
pending requests.
* When creating an artist by clicking the '?' next to the artist tag in
the tag list, prefill the new artist form by finding the artist's last
upload and fetching its source data.
Previously we filled the urls with the source of the artist's last
upload, which was wrong because it was usually a direct image URL (#3078).
* Fix the other names field not escaping spaces within names to underscores.
* Fix the other names field being potentially prefilled with duplicate names.
* Normalize spaces to underscores when saving other names. Preserve case
since case can be significant.
* Fix WikiPage#other_names_include to search case-insensitively (note:
this prevents using the index).
* Fix sources to return the raw tags in `#tags` and the normalized tags
in `#normalized_tags`. The normalized tags are the tags that will be
matched against other names.
Fix exception in Pool#previous_post_id when the post id is not contained
in the pool.
This can happen when a post's pool_string lists the post as being in a
certain pool, but the post is not included in the pool's post_ids. Such
pool_string / post_ids inconsistencies exist because of past bugs.
* Rename Upload#download_for_upload to #get_file_for_upload.
* Fix #get_file_for_upload to raise error if no file or source url was given.
* Fix javascript upload validation to disallow submitting form if file is
not present and the source is not an url.
* create_mod_action_for_destroy didn't exist (pools are never destroyed).
* is_active and is_deleted are already initialized via database defaults.
* creator_name is already defined by belongs_to_creator.
* Returning true/false in validations does nothing.
Convert to an autosave association on urls. This ensures that when we
save the artist we only validate the added urls, not bad urls that we're
trying to remove, and that url validation errors are propagated up to
the artist object.
This also fixes invalid urls being saved in the artist history despite
validation failing (#3720).
