Rebase on Upstream

This issue is a meta issue to track questions related with rebasing our current codebases back on Upstream.

Related upstream issues are:

Plugin System (open since 29.12.2011 !!!)
https://github.com/frab/frab/issues/10
Make event types configurable (18.03.2017)
https://github.com/frab/frab/issues/302
- configurable event types per conference (opened 03.09.2019 - merged 25.10.2019)
  https://github.com/frab/frab/pull/530
README.PaaS.md should require a persistent storage (open since 06.03.2019)
https://github.com/frab/frab/issues/466

Edited Nov 15, 2019 by jon r

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information