Changed the representation of scsh-conditions to the exception

os-error so it may be throwen from C.

scsh/scsh-condition.scm

@@ -9,19 +9,26 @@
 
 (define (errno-error errno syscall . stuff)
   (let ((msg (errno-msg errno)))
-    (apply signal 'syscall-error errno msg syscall stuff)))
-
+    (apply (structure-ref exceptions signal-exception) 
+	   (enum op call-external-value) (enum exception os-error) 
+	   syscall errno msg stuff)))
 
 (define (with-errno-handler* handler thunk)
   (with-handler
     (lambda (condition more)
-      (if (syscall-error? condition)
-	  (let ((stuff (condition-stuff condition)))
-	    (handler (car stuff)	; errno
-		     (cdr stuff))))	; (msg syscall . packet)
+      (if (and (exception? condition) (eq? (exception-reason condition) 
+					   'os-error))
+	  (let ((stuff (exception-arguments condition)))
+	    (handler (cadr stuff)	; errno
+		     (list (caddr stuff)  ;msg
+			   (car stuff)    ;syscall
+			   (cdddr stuff) ;packet
+			   )))) ; (msg syscall . packet)
       (more))
     thunk))
 
+
+
 ;;; (with-errno-handler
 ;;;   ((errno data) ; These are vars bound in this scope.
 ;;;    ((errno/exist) . body1)