Create self service method to synch accounts

addon to option 2 in #1: Since we pretty much automatically wipe out g.d.o created accounts, we need to send out an email to the current accunt holder before the takeover notifying them of the event. They will receive a post-factum email, but at least that gives them some information on what happened and chance to "handle it" later. Also if a user comes back to us with such email, it gives us a trailback. My take on it is if a user didnt come back to us, the trailback is not important.

Claiming.

Here's what I have so far.

I may be coding a bit too defensively when it comes to {users}.init, but as that field isn't unique, it really needs to be watched carefully.

Also, it would be a very good idea on largeish sites to add an index on {users}.init to speed things up.

States a user can be in:

A) username and mail both match -- they get logged in because that's the criteria for logging in with the cookie
B) username matches, email doesn't -- Fixable with confirmation
C) username differs, email matches -- Fixable with confirmation
D) username matches one account, email matches another account -- Only fixable by manual process because both accounts will need to be modified because only one user can have the same name and only one user can have the same email
E) Username and email match, but init is wrong -- Means that if the user makes changes on their master account it will go out of sync. This is fixable automatically.
F) Username and/or email differ, but init matches -- This is fixable automatically.
G) Any of the above, with the additional problem that a DIFFERENT account has a matching init. -- This is bad.
H) Multiple accounts with matching init. -- This is bad.

Tested this out and it works well. The code also looks decent. +1 for keeping up with the whimsical function names.

This will help us out going forward on g.d.o, but we should be aware it won't resolve accounts where the names AND emails are different (which is a non-trivial set). Still, it should be included IMHO, as it makes Bakery more usable by the wider world.

The only thing I'd like to see for this is some better bakery_uncrumble_submit() comments and function documentation.

If possible we should get a second set of eyes on this, but it worked well for me and the code is nice and clean. Great job BDragon!

I am ok with this.

Ok, I'm going to roll this in and put it on g.d.o this weekend if nobody objects.