small improvement of "open latest"

[hjaaj]

It is not super important, but it would be nice if the recent files list also included this:

I opened a file, used "save as" to save it under a new name, made some changes, saved and closed.

Next time I opened MacVim, the latest files list only contained the original name, not the name I gave it with "save as".

Thank you for maintaining MacVim, it is a great tool for me!

Best regards, Hans Jørgen.

[ychin]

I could take a look some time later. Right now that list isn't very well integrated with the rest of Vim (e.g. it won't popular files you open using :e) so I kind of want to think about how it should work.