How to port your A26 mod to A27

This lists (most) of the template-changing commits, and how to fix them. And also some other breaking changes.

r27114 & r27115

Move unit portraits to their own specific folders. Modders can change their templates with the script at ​MISSING.

r27169

The minimap now requires a background per civilization. It should be placed in session/icons/bkg/ and named background_circle_{civ}.png You can also remove that feature by editing gui/session/minimap/MiniMapPanel.js or adding exclusions.

r27245

The requirements of training and upgrades are now handled by a Requirements helper. The schema of both is unified. One can fix the templates with: ​https://code.wildfiregames.com/P265.[[BR]]