Ticket #280 - extensible binary filters do not work
    
    https://fedorahosted.org/389/ticket/280
    Resolves: Ticket #280
    Bug Description: extensible binary filters do not work
    Reviewed by: nkinder (Thanks!)
    Branch: master
    Fix Description: The code was using strdup to copy the value when dup'ing
    the filter.  We already had code that copied the contents of binary
    bervals, so I just put slapi wrappers around them and created and
    documented two new slapi functions - slapi_ber_bvcpy and slapi_ber_bvdone.
    I found a few places that were manually copying the contents of bervals
    and replaced them with slapi_ber_bvcpy and slapi_ber_bvdone.  With this
    code the filter, I18n, and index tests pass at 100%.
    Platforms tested: RHEL6 x86_64, Fedora 16
    Flag Day: yes - slapi-plugin.h change
    Doc impact: yes - two new slapi functions