Improves the look of the error mesages in the REPL.

loop.lisp

@@ -212,7 +212,10 @@
         (print/finish "^C~%")
       (uiop:quit 0))
       (t (c) 
-        (print/finish "Oops: ~a~%" c)))))
+        (print/finish 
+         "Oops: ~a~%" 
+         (str:collapse-whitespaces 
+          (str:replace-all (string #\linefeed) " " (fmt "~a" c))))))))
 (defun empty-response () (make-response :code 400 :data "I beg your pardon?"))
 (defun prepend-response-with (message r)
   (make-response 

loop.nw

@@ -426,7 +426,10 @@ line, which is what causes that 400 response.
         (print/finish "^C~%")
       (uiop:quit 0))
       (t (c) 
-        (print/finish "Oops: ~a~%" c)))))
+        (print/finish 
+         "Oops: ~a~%" 
+         (str:collapse-whitespaces 
+          (str:replace-all (string #\linefeed) " " (fmt "~a" c))))))))
 @ %def repl
 
 \section{Description of the package}