Merge remote-tracking branch 'origin/stable-2.0'

Conflicts:
	module/srfi/srfi-9.scm
	module/web/server.scm

diff --cc doc/ref/api-io.texi
Simple merge

diff --cc module/ice-9/boot-9.scm
Simple merge

diff --cc module/ice-9/psyntax.scm
Simple merge

diff --cc module/srfi/srfi-9.scm
Simple merge

diff --cc module/web/server.scm
index affc2e6,99196fa..471bb98
--- 1/module/web/server.scm
--- 2/module/web/server.scm
+++ b/module/web/server.scm
@@@ -164,14 -165,9 +165,11 @@@ values.
     #:post-error (lambda _ (values #f #f #f))))
  
  (define (extend-response r k v . additional)
-   (let ((r (build-response #:version (response-version r)
-                            #:code (response-code r)
-                            #:headers
-                            (extend-alist (response-headers r) k v)
-                            #:port (response-port r))))
 +  (define (extend-alist alist k v)
 +    (let ((pair (assq k alist)))
 +      (acons k v (if pair (delq pair alist) alist))))
 -                      (assoc-set! (copy-tree (response-headers r))
 -                                  k v))))
+   (let ((r (set-field r (response-headers)
++                      (extend-alist (response-headers r) k v))))
      (if (null? additional)
          r
          (apply extend-response r additional))))