Introducing a new feature for setting window behaviour via policies, based on usual selectors like window class, name, type. Those policies are matched against the selector elements (or wildcards) and set certain attributes for matching windows.
For now just implementing two policy attributes for initial positioning:
- placement.geometry: set initial position / size
- placement.midpoint: set midpoint of initial position
- force.border: enforce a border for window, even if the application doesn't have it