Synchronize pushing to Bukkit perms to prevent any
ConcurrentModificationException.
Fix the logger so errors are reported again.
Do not grant any permissions (nort update Bukkit) if the server is in
offline mode and the player has the permission node
'groupmanager.noofflineperms'.
typo in changelog.
Merge remote-tracking branch 'remotes/origin/groupmanager' into 2.9