Etiquette

This is the readme file.

Make the wording between "new", "create", "add"; and "remove", "delete" more consistent.
User account system, permission levels, private pages.
Improve the "tags on this page" list. Maybe add separate buttons for must/may/forbid on each.
Some way for the database to re-identify a file that was moved / renamed (lost & found). Maybe file hash of the first few mb is good enough.
Debate whether the UserMixin.login method should accept usernames or I should standardize the usage of IDs only internally.
Album size is calculated every time you refresh the page. For large albums this is very slow. Consider caching? Or saving to db?
Organize the tag exporter functions better.

[addition] A new feature was added.
[bugfix] Incorrect behavior was fixed.
[change] An existing feature was slightly modified or parameters were renamed.
[cleanup] Code was improved, comments were added, or other changes with minor impact on the interface.
[removal] An old feature was removed.