- Removed ZIP system for now, until the idea can be fleshed out.
- Added testing to cover.
- Upgraded used library.
- Added custom handling for BookStack callouts.
- Added HTML cleanup to better produce output for things like code
blocks.
Removed some common functions from other entities.
Aligned implementation of getUrl()
Cleaned phpdocs and added typehinting.
Also extracted sibling search logic out of controller.
Tools seems to fit better since the classes were a bit of a mixed bunch
and did not always manage.
Also simplified the structure of the SlugGenerator class.
Also focused EntityContext on shelves and simplified to use session
helper.