Write Release Goals for GDP 13

Although we're working a lot more agile now, with the ability to do more frequent re-prioritization of the backlog, some outlook for GDP13 content still makes sense (and has been requested):

• Review the remaining calendar with planned absence etc. until AMM date
• Write main features and goals we want to achieve
• Start to re-prioritize tickets accordingly
• Make an estimated guess on what fits and doesn't