! New hook for post-registration notifications (once we have the user's new id), fixes #242 (there's already a hook for the register_validate part called register_check, this adds the other hook as suggested)

Signed-off-by: Peter Spicer <sleeping@myperch.org>
Merge pull request #677 from Arantor/release-2.1

! New hook for post-registration notifications (once we have the user's ...