changes in sbcl-0.6.11 relative to sbcl-0.6.10:

* Martin Atzmueller pointed out that bugs #9 and #25 are gone in
  current SBCL.
* bug 34 fixed by Martin Atzmueller: dumping/loading instances works
  better
* fixed bug 40: TYPEP, SUBTYPEP, UPGRADED-ARRAY-ELEMENT-TYPE,
  and UPGRADED-COMPLEX-PART-TYPE now work better with of compound
  types built from undefined types, e.g. '(VECTOR SOME-UNDEF-TYPE).
* DESCRIBE now works on structure objects again.
* Most function call argument type mismatches are now handled as
  STYLE-WARNINGs instead of full WARNINGs, since the compiler doesn't
  know whether the function will be redefined before the call is
  executed. (The compiler could flag local calls with full WARNINGs,
  as per the ANSI spec "3.2.2.3 Semantic Constraints", but right now
  it doesn't keep track of enough information to know whether calls
  are local in this sense.)
* Compiler output is now more verbose, with messages truncated
  later than before. (There should be some supported way for users
  to override the default verbosity, but I haven't decided how to
  provide it yet, so this behavior is still controlled by the internal
  SB-C::*COMPILER-ERROR-PRINT-FOO* variables in
  src/compiler/ir1util.lisp.)
* Fasl file format version numbers have increased again, because
  support for the Gray streams extension changes the layout of the
  system's STREAM objects.
* The Gray subclassable streams extension now works, thanks to a
  patch from Martin Atzmueller.
* The full LOAD-FOREIGN extension (not just the primitive
  LOAD-FOREIGN-1) now works, thanks to a patch from Martin Atzmueller.
* The default behavior of RUN-PROGRAM has changed. Now, unlike CMU CL
  but like most other programs, it defaults to copying the Unix
  environment from the original process instead of starting the
  new process in an empty environment.
* Extensions which manipulate the Unix environment now support
  an :ENVIRONMENT keyword option which doesn't smash case or
  do other bad things. The CMU-CL-style :ENV option is retained
  for porting convenience.
* LOAD-FOREIGN (and LOAD-1-FOREIGN) now support logical pathnames,
  as per Daniel Barlow's suggestion and Martin Atzmueller's patch