http: fix multipart reply

fixes compatibility with libneon ( davix and ROOT )

after second reading of http://tools.ietf.org/html/rfc2616
each Range block should not contain Content-length, but
complete requests must.

Acked-by: Gerd Behrmann
Target: master, 2.8, 2.7, 2.6
Require-book: no
Require-notes: no
(cherry picked from commit 702c68b36d369876a70a5ef8cf81dded9cf740ec)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
http: adjust unit test to multirage changes

Acked-by: Paul Millar
Target: master, 2.8, 2.7, 2.6
Require-book: no
Require-notes: no
(cherry picked from commit a000a7301b9ef31bfc35d184d367bf98f3344784)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #462 from kofemann/fix-http-davix-2.6

http: fix multipart reply
[maven-release-plugin] prepare release 2.6.23
[maven-release-plugin] prepare for next development iteration
nfs-proxy: fix logging CDC

Acked-by: Gerd Behrmann
Target: master, 2.8, 2.7
Require-book: no
Require-notes: no
(cherry picked from commit 6e7943fe960f165ab9474188c59c79bc6f61c64a)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge remote-tracking branch 'upstream/2.6' into 2.6-backport-proxy-io