[FIX] perms: Check object perms for rename (and no longer any need to set global perm vars with get_perm_object fn)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49674 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] perms: Check object perms for structure editing (thanks eromneg)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49675 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] perms: Don't show categories the user doesn't have view_category perm for (thanks eromneg)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@49677 b456876b-0849-0410-b77d-98878d47e9d5