Add 'can_owner' flag to *Rule

This flag defines if the "Owner permissions on/off" button gets
displayed in aa-logprof.

False by default for all rule types (most of them don't support the
owner conditional). Also false for non-owner FileRule.

True only for FileRule if owner=True.

utils/apparmor/rule/__init__.py

@@ -46,6 +46,9 @@ class BaseRule(object):
     # defines if the (N)ew option is displayed
     can_edit = False
 
+    # defines if the '(O)wner permissions on/off' option is displayed
+    can_owner = False
+
     def __init__(self, audit=False, deny=False, allow_keyword=False,
                  comment='', log_event=None):
         '''initialize variables needed by all rule types'''

utils/apparmor/rule/file.py

@@ -104,6 +104,7 @@ class FileRule(BaseRule):
         if type(owner) is not bool:
             raise AppArmorBug('non-boolean value passed to owner flag')
         self.owner = owner
+        self.can_owner = owner  # offer '(O)wner permissions on/off' buttons only if the rule has the owner flag
 
         if type(file_keyword) is not bool:
             raise AppArmorBug('non-boolean value passed to file keyword flag')