all of guile compiles now, expanded with syncase

* libguile/eval.c (scm_m_eval_when): Whoops, eval-when has an implicit
  begin. Fix.

* module/oop/goops.scm: Syncase doesn't like definitions in expression
  context, and grudgingly I have decided to go along with that. But that
  doesn't mean we can't keep the old semantics, via accessing the module
  system directly. So do so. I took the opportunity to rewrite some
  macros with syntax-rules and syntax-case -- the former is nicer than
  the latter, of course.

* module/oop/goops/save.scm: Don't define within an expression.

* module/oop/goops/simple.scm (define-class): Use define-syntax.

* module/oop/goops/stklos.scm (define-class): Use define-syntax.

module/oop/goops/save.scm

@@ -110,9 +110,7 @@
 ;;; Readables
 ;;;
 
-(if (or (not (defined? 'readables))
-	(not readables))
-    (define readables (make-weak-key-hash-table 61)))
+(define readables (make-weak-key-hash-table 61))
 
 (define-macro (readable exp)
   `(make-readable ,exp ',(copy-tree exp)))