-Properly re-wrote the go-sexp function and accompanying infrastructure
-Still need to handle comments, proper strings, and figure out one or two gotchas with skipping whitespace to the :left
-Fixed some subtle alignment bugs (turns out I was right the first time; the char-at and type-at coordinates are mis-aligned by one, which was causing some off behavior that's now been corrected)
-Proper forward/backward s-exp movement is now a thing. Kill should be a straightforward elaboration, and slurp/barf shouldn't be TOO much worse.
-Still need to put together proper line-jumpting (Ctrl+Up/Ctrl+Down should go to the next blank line in the appropriate direction)