TODO for cl-launch as of 2.31

 * When resuming from an image then dumping another, the INCLUDE_PATH
   becomes a very bad variable to look for the image.
   Include a test case and fix it.
   More generally, test with directory differences between image and
   other stuff.

 * Maybe: add "dump from previous image" support for ECL?
   One limitation that cl-launch has on ECL (vs on e.g. SBCL)
   is the inability to "dump an image from a previous image".
   This could be achieved by hacking asdf:make-build
   (from ecl/contrib/asdf/asdf-ecl.lisp) to intercept in a
   (defmethod perform :before ((op monolithic-bundle-op) (c system)) ...)
   the arguments to the last call to c::builder, and to re-inject those
   arguments in same call them the next time around, assuming
   (which is somewhat fragile) that objects won't have been moved or
   deleted by then. I do not currently intend to support this feature
   in cl-launch, but will hopefully support it in XCVB that can do the
   bookkeeping on its side.
