I think adding it to acs-tcl or adding an acs-util package is
the wrong way to go. If you look at acs-subsite for example one of the biggest problems is that it is such a catchall, you can't have a subsite which does not have admin pages, there are a ton of pages in the url space you may or may not want in a given subsite.
I think there is nothing that says the api can't go in acs-tcl and the ui in a rel-ui package (that's what I would prefer really).
