ZideStore Backend
=================

Wrapper library around OGo database and commands. Notably ZideStore backend
sometimes uses direct SQL access to tables for faster operation.
This should be moved to real commands in the future.

A lot of the queries operate in the context of a "set". A set is basically
a qualifier which restricts the operations on a certain subset of an OGo
table.

TODO: write much more

Class Hierarchy
===============

  [NSObject]
    SxAptSetIdentifier
    SxBackendManager
      SxAptManager
      SxContactManager
      SxTaskManager
    SxBackendMaster
    SxContactSetIdentifier
    SxFreeBusyManager
    SxRecordCacheManager
    SxSQLQuery
      SxContactSQLQuery
        SxContactEmailSQLQuery
        SxEvoContactSQLQuery
        SxListContactSQLQuery
        SxZLContactSQLQuery
    [NSEnumerator]
      SxSQLQueryResultEnumerator
    SxSetCacheManager : NSObject
    SxUpdateContact
      SxUpdateEnterprise
      SxUpdatePerson
    SxAppointmentRenderer
    SxAptSetHandler
    SxFetchContact
      SxFetchEnterprise
      SxFetchGroup
      SxFetchPerson

Apt
===
ZLAptLogChanges              - BOOL
SxAptFolder_MonthsIntoPast   - int (2)
SxAptFolder_MonthsIntoFuture - int (12)