Drop many uses of "gracket" and "gracket-text" in drdr command-lines.
Drop many uses of "gracket" and "gracket-text" in drdr command-lines.

There were many such properties that were leftover from before the big
GUI rewrite where the gracket executable was needed, and now there is no
longer any need for these things.  There are two exceptions:

* There is a drdr feature that forces all tests that use gracket to run
  sequentially, which is used for tests that rely on some actual state
  of shown windows.  I ran all of the files and monitored for windows
  popping up, and left the test to use gracket in these cases.

* There are a few cases where running "racket -f <file>" resulted in an
  unbound identifier, whereas "gracket -f <file>" does not.  These are
  because of the different global namespace, and I will fix them (props
  and the files) in a different commit.

One of the expected results of this is that a drdr might run faster,
because the serial-running hack above should now be applied only where
relevant.  (And some of the drracket tests are very long.)

This commit is pushed by itself to identify possible problems with a
drdr run that tests only this change.

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket