[development] invite module

[Khalid B]

Hello all.

I am thinking of deprecating my referral module in favor of invite module,
now that 4.7 (and not HEAD) has hooks that I can use in adsense and
userpoints. This avoids code duplication and user confusion.

There is a need to add more hooks at certain points (e.g. when invited
user actually registers, before role escalation),

Also, there is a need to add some sort of callable query on whether a
certain uid was  referred by another?

Upon contacting Robert Douglass (who did the last round of changes to
that module) he agrees with my proposed additions. I tried to contact
Tatonca (Christopher Hill), but no reply since.

So, I am asking here once more in case Chris lurks around. If do not
hear from him in a few days, I will take over temporary ownership of
the module, add the hooks in, update HEAD to 4.7.

Any objections, comments, flames?