Resolves: bug 457846
    Bug Description: The Windows Sync API should have plug-in points
    Reviewed by: nkinder (Thanks!)
    Fix Description: Some additional changes to the api
    1) added plugin points for begin update, end update, and agreement destruction
    2) added debugging code to allow a regular DS to stand in for AD
    3) fixed a couple of minor memory leaks
    4) added the rest of the SLAPI DSE code to the public API to allow plugins to do dynamic configuration using the SLAPI public API
    Platforms tested: RHEL5
    Flag Day: no
    Doc impact: yes - plugin guide