Milestone 2

I was able to catch up on the research this week and should now be able to start proper brainstorming and planning next week. Contrary to the expectations, SIREn doesn't seem to have been released yet, so the corresponding task will be delayed until the real release.
Instead I started catching up on the development of the apachesolr module, which I seem to really need by now.

Completed tasks:

• #478110
• #478112

Postponed:

• #478116

Up next:

• #484726
• #484730