Remove option to return values from break loop in many places

[ChrisJefferson]

This removes the option to return a value from the break loop in many places (in particular, places Max just cleaned up).

This isn't all places, but I thought I'd make this simple pass first, then work through the other cases in further PRs.

[fingolfin]

Looks good to me. But I wonder: Are any calls to RequireArgumentConditionMayReplace left in there? If yes, why? If no, how about removing RequireArgumentConditionMayReplace and its various wrappers from error.h?

[ChrisJefferson]

I wasn't sure if those functions might end up being wanted at some point in packages, or the library. I'm happy to delete them.

[fingolfin]

Well, I see it like this: if somebody really wants those *MayReplace variants, they better have a really strong convincing argument; and then we can add them back. In the meantime we want to remove (and hence also discourage) this style of coding, don't we? Hence I'd remove them. Alas, that certainly can be done in another PR. No need to delay this one for it.