Reorder and restructure agenda

[benjie]

Todays agenda was massive, so I've restructured it:

• grouped together my editorial PRs
• grouped together Martin's editorial PRs
• with Martin's permission moved a few of his items to the end as a "call for async feedback"
• grouped Martin and my "before execution begins" solutions and will present them together
• tried to vary the speaker for fairness
• moved announcements to the top
• indicated how close some of these are to merging
• implemented standard formatting for the items
• removed reviewing of agenda items