> And in any sort of deployment situation one would not want all the  
> test code
> sitting around.

Exact

> It might be worth making some sort of sibling relationship so
> that loading doesn't require loading the tests but _does_ tell us  
> that there is
> a related test package and does make it trivial to load it.

yes this is what we learned the hard way (impossible to go in the  
past and identify the tests
covering the right version old version).

I have the impression that having the same number for tests than for  
the package works

PA1             PAT1
PA1.2           PAT1 "nothing changes in the tests
PA2             PAT1 "nothing
PA3
PA4             PAT4 "tests changes to cover version 4"
PA4             PAT4.1 "fixed tests alone
PA5             PAT4.1
PA6             PAT4.1
PA7             PAT7  "tests changed and are in sync with package7