Creator power level in room version 12

Previously, the specification defined the power levels of users as follows:

Room version 12 defines the power levels of users as follows:

Note in both cases clients need the m.room.create event and m.room.power_levels event to accurately determine the power level of users. Since most rooms have a m.room.power_levels event, many clients failed to implement first branching “no” in v1-v11 rooms. The new rules take into account the privileged position of room creators whilst also ensuring that clients implement the full decision flow chart.