The better implementation of a224297.
Fixes ability to reorder tag aliases, especially - the ability to change
the tag's primary name after it was created. Until now, both of these
scenarios needed sad workarounds on the user part.
- Don't cache default category in its entirety - cache only its name
- Purge cache on category name changes and default category changes
- Lock records for updates where applicable
Rather than flushing the post right away only to find out that there
were validation errors, try to postpone flushing for as long as
possible.
The previous behavior has led to too eager spending of post IDs - each
flush calls nextval(post_id_seq), and postgres sequences are not
affected by transaction rollbacks, so each erroneous post creation
discarded a post ID, which has led to gaps in post IDs.
This changes the checksums to ones that are compatible with 1.x, which
relieves the migration script from recalculating the checksums for all
the posts.
Ignored only the rules about continuing / hanging indentation.
Also, added __init__.py to tests so that pylint discovers them. (I don't
buy pytest's BS about installing your package.)
rr-