Code review comment for lp:~alan-griffiths/mir/remove-BufferInitializer

Its one of the older classes in the code, and I agree that it hasn't gotten much useful customization and use, so I'm okay with its removal. This does break platform api, not sure what to do about that (sometimes we increment, sometimes we don't). I'd guess because this doesn't reach very far outside of the mir project we shouldn't increment. Apart from that issue though, approve.