* fix: keep file permissions set by Windows programs on volumes without extended attributes
Wine's server stores a file's security descriptor in an extended attribute.
Volumes that cannot hold one dropped every descriptor, so a program that
checks and repairs its install folder's permissions repeated the repair on
every start. The descriptor is now kept inside the prefix when the volume
refuses it, and follows the file when the server renames or deletes it.
* fix: a path deleted with remove() drops its kept descriptor too