Check subgroup permissions with an equal priority so no one subgroup is higher ranked than another.
add recursive permission adding/removing

also other minor fixes
Improve Javadocs, clean ' strip checks, update changelog.
Tidy imports
Fix Cyclic mirroring test (silly me)
Change to use LinkedHashSets to preserve ordering. Fixes an issue with populating bukkit perms in the wrong order. Fix wildcard negation in parent groups.
Allow Exception permission to override negations when in the same group.
Prevent adding sub groups for ranks the granting player doesn't have access to.
Cleanup plugin description
Allow Exceptions in any inherited group to override negation of permissions.
Fix manucheckp to understand and report correctly on Exception nodes.
Update mangcheckp to understand Exception nodes.
Fix a /mangcheckp message
Do not override higher level permissions with negations.
v2.1: - Update for CraftBukkit 1.7.8-R0.1(3050). - Add UUID support. Plugins can still query by player name but a UUID is faster and preferable.
Fixup javadocs
Fix overloadedWorldHolder so it correctly calls the new WorldHolder code when the user is not overloaded.
Set a default mirror map if none is found in the config.
Fix clones forgetting sub groups.
Allow disabling userfile cache on uuid convert.
Add "ignore-userfiles-cache: true" to "upgrades-done.yml" to disable cache, forcing uuid lookup requests.