[5.6] Rename setGlobalTo to setGlobalToAndRemoveCcAndBcc

[colindecarlo]

I spent a bunch of time earlier tonight trying to figure out why the cc addressee I was setting in my Mailable wasn't receiving a copy of the email I was sending. Turns out the setGlobalTo method in the Mailer removes the cc and bcc recipients.

This change may prevent future devs from banging their heads against this.

[devcircus]

If I'm remembering correctly, this has been discussed before. The global "to" address exists jug for development for the purpose of replacing any recipients, so that emails don't get sent to someone accidentally while developing. IMO, the current behavior is correct. On the other hand, other devs have mentioned this before, so I guess there's room for discussion. I'll try to find the old issue /pr related to this.

[colindecarlo]

Ha, this PR was a little tongue in cheek, no real motivation other than to work out my own frustration for banging up against this.

The documentation does a pretty good job of saying that the 'Universal To' is meant for local development.

I was using it in a "real" app I made for a family member that sends one email as a sort of 'contact us' submission.

With that said, the method name is certainly more accurate now :)