Add some more VoiceOver.

I'm not sure adding the "author", "original poster", etc. are all that helpful in the posts view, but there's no other way to get that info.
Fix OP not being indicated in posts view.
Cancel image uploads when backing out of a post/message/thread preview screen.
No need for #pragmas.

Still questionable API decisions though. :sigh:
Fix "post"/"preview" button not enabling after inserting an image into a previously empty text view.