AI 143486: Update diff tool rules in webkit makefiles.

AI 143486: Update diff tool rules in webkit makefiles.
  Anticipating another merge with webkit, these changes
  update the rules to automatically exclude files we've already removed
  manually. A new rule allows including files that are not yet
  checked into webkit's makefiles (e.g., Touch).
  The exclude rules no longer need to be alphabetized, but the
  makefile sources still do -- so fix a couple of entries that
  are out of order.
  BUG=1553405

Automated import of CL 143486