webadmin: fix jquery and Co. with new wicket

wicket 6.9.x comes with own jquery library.
remove the old version. Update pages to use
included version. Update page rendering to
include required scripts.

This change fixes regressions introduced by
migrating to wicket 6.9.1 [55f703e].

Acked-by: Albert Rossi
Target: master, 2.7
Require-book: no
Require-notes: no
webadmin: sort domain entries on CellAdmin page

On a installation with 600 domains it's hard to find
required Domain/Cell.

Acked-by: Paul Millar
Target: master, 2.7
Require-book: no
Require-notes: yes
Merge remote-tracking branch 'upstream/2.7' into 2.7
Merge pull request #161 from kofemann/2.7

webadmin fixes