Proposal to move the module post install hook to after the site course setup

The new hook in 1.9 that allows a module to do some stuff post db install is awesome. However it would be more useful if the call was done later in the install process, once the site course is set-up.

Doing the call post site course set-up would allow module to make role overrides and on the site course and other such things and would basically maximise the usefulness of the hook.

I know nothing in core is using the hook, so unless there's a contrib module relying on the call it should be safe to move without breaking anything.

Any feedback is welcome.