[racket] Change DrRacket autosave/backup file locations?

Hi all,

Is it possible, via .racketrc, preferences, or some other mechanism, to change where DrRacket saves backup and preference files?

Reason: Using DrRacket to edit programs stored in Dropbox, the presence of such temp files in my Dropbox folder is introducing a lot of noise in the Dropbox activity log.  (I know, I know, I can use git or another version control system...but for the very short coding projects I usually do, that seems like overkill, really.)

Best,
Jordan