Elgg/Elgg — pull request #6680 by juho-jaakkola (2014-04-01 17:46:11+00:00)
Title: Instructions on upgrading plugins for Elgg 1.9

**This is WIP. Do not merge.**

We need to decide:
- Do we want to include plugin upgrade instructions to the rst docs?
- How detailed information do we want to include?
- Is ```guides/``` the correct place for this doc?