[xwiki-devs] [proposal] Make filesystem attachments use permanent storage directory instead of work dir.

Hi, I'd like to switch filesystem attachments to begin using the persistent storage directory now instead of the work directory. This means there's a new way of calculating where the attachments will be stored so it might fail on upgrade. I would like to not do any migration and just add to the release notes because: #1, it doesn't cause any permanent harm so long as nobody adds attachments while it's in what is an obviously broken state. #2 administrators who have FS attachments enabled are probably going to know what's going on. #3 migration code is scary, it requires lots of work and lots of review and even if it works, people might feel violated having files shuffled around on their system without their permission. WDYT? Caleb