1.0.20.29: small FIND fix & win32 build fix

1.0.20.29: small FIND fix & win32 build fix

 * FIND on lists should not call the KEY function outside the
   specified subsequence.

 * Hopefully fix Win32 build: #+/#- -> #!+/#!- changes to pacify
   SHE-READER.

 * Also advice against editing version.lisp-expr in Git, and show the
   branch-version.lisp-expr hack in GIT-FOR-SBCL-HACKERS.txt.