Scrolling / positioning fixes

There are two issues with scrolling and positioning that bother me.

First, it frustrates me how Scrivener remembers (or not) the position that I’ve scrolled to in a document. Often I switch to a document, scroll to some position to read a piece of text or refresh my memory, then go back to my active document. Then the next time (sometimes just minutes later) I go back to the other document to read again, the scroll position has reset to some other location. In Scrivener 2, it seemed to remember the caret position, so I got used to clicking on the screen to move the cursor to where I was reading. Even that frustrated me, since I felt the scroll position should be remembered without it, but now even that doesn’t seem to work reliably.

Second, I really like the typewriter mode of scrolling in composition mode. It’s very nice to keep the text I’m writing at the center of the screen. However, it doesn’t work properly on blank documents, since in that case the cursor/ scroll position ends up at the top of the screen. Given that it’s called typewriter mode, it makes sense to me to have the cursor be in the middle of the screen even when the document is empty. If that was confusing to people for some reason, it would probably help to have a visual indicator of the top of the ‘page’, by having the page background end a little above the cursor and then having the dark composition background above that.