Multi Module follow up tasks

[kleingeist]

This issue is meant to track follow up tasks from the multi module changes. They result mostly from comments in #144 #153 and offline discussions.

• Update phases.md
  • [x] Rename to modules_and_phases.md
  • [ ] Unify structure (Adapt modules structure to phases)
  • [ ] Ensure "hide features if not usable in a module" is really solved (see: https://github.com/liqd/adhocracy4/pull/153#discussion_r132890136)
• [ ] Decide if timeline should become a core feature
• [ ] Decide if phases should be sorted by 'start_date' by default (will be breaking for dashboards) (see: https://github.com/liqd/adhocracy4/pull/153#discussion_r132884386)
  • [ ] Decide and document where to expect Phases without a date. For example after every phase with a set date. This is relevant for Project previews
• [ ] Remove unused PhasesQuerySet.finished_phases
• [ ] Set request.project and document that request.module and request.project are valid request properties (see: https://github.com/liqd/adhocracy4/pull/153#discussion_r132885867)
• [x] Decide if overlapping phases should be conceptually allowed
  • [x] ~~if yes: remove Project.active_phase and adapt Project.days_left~~
  • [x] if no: remove deprecated comment and document the restriction
• Decide on 'days_left' display on project tile and 'phase over soon' actions.
  • [x] Decide on days_left of project (=last phase) or current phase
  • [x] Decide when to send phase over soon emails wit multiple overlapping modules and how to word them
• [ ] Decide if Actions should point to modules instead of projects

[fuzzylogic2000]

@MagdaN Here are some thoughts concerning timeline and so on

[philli-m]

@fuzzylogic2000 are most of these done now?