leihs 3.15.0 now available

This is big new for database reliability and consistency:

• There are now strict foreign key constraints in the leihs database. This means it should be much harder for you to ever end up with inconsistent data (e.g. an item without an owner, a user that's a member of a group that doesn't exist anymore, etc.)

Please note that you need leihs 3.14.0 and a consistent database to upgrade to 3.15.0 and higher. The upgrade process is described in the guide:

https://github.com/zhdk/leihs/wiki/leihs-Admin-Guide#upgrading-from--3140-to--3140