*fix* correct transient window handling (f.ex window3 is transient for window2 and window2 transient for window1 and window1 is already in tint2, so window3 will not be added) git-svn-id: http://tint2.googlecode.com/svn/trunk@542 121b4492-b84c-0410-8b4c-0d4edfb3f3cc