1.0.28.38: undefined warning and compilation unit summary tweaking

1.0.28.38: undefined warning and compilation unit summary tweaking

 * Signal a full warning for undefined types when the name is in the
   COMMON-LISP package.

 * Explain probable source of error when the name of an undefined type
   is a quoted object.

 * When same original source form is responsible for multiple
   undefined warnings, only signal the first: otherwise we may signal
   a boatload of identical warnings for a single source form just
   because the compiler tries so very hard to make sense of it.

 * Don't summarize the names of undefined things by signalling new
   warnings for them, instead include the names in the compilation
   unit summary.