Rework EFI partition management logic (Bug#1092892)
See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1092892
- Remove interaction with the 'boot' flag and the 'bootable' file.
- Remove the 'esp' flag on existing and new EFI partitions when the method is set to another use.
- Remove the 'esp' flag on new EFI partitions when the method is set to "do not use".
- Preserve automatic recipe or user's choice to not use existing EFI partitions.
In order to preserve unused existing EFI partitions (which may be used by other OS):
- Keep the 'esp' flag on existing EFI partitions when the method is set to "do not use".
- Restore the 'esp' flag on former existing EFI partitions when the method is set to "do not use".
- Forget about former EFI partitions when committing changes.
Edited by Pascal Hambourg