(2.6)dcache-webadmin: fix page update; fix sorting

    Version of 6082 & 6083 ported back to 2.6

    Testing:  as with patches for master.

    RELEASE NOTES:
    Fixes an issue with some of the tables in the webadmin service which were not refreshing.  Update correctly occurs now on reload, resubmission of the form through link clicking, and on many pages by automatic page refresh.
    Fixes issues preventing the sorting of tables and subtables in webadmin.

    Target: 2.6
    Require-notes: yes
    Require-book: no
    Bug: http://rt.dcache.org/Ticket/Display.html?id=7929
    Bug: http://rt.dcache.org/Ticket/Display.html?id=7964
    Bug: http://rt.dcache.org/Ticket/Display.html?id=7983
    Acked-by: Gerd
    Acked-by: Tigran