Trac Ticket #531 - loading an entry from the database should use str2entry_fast
    
    https://fedorahosted.org/389/ticket/531
    
    Bug Description: When loading an entry from the backend, it
    is known to be well formed and str2entry_fast() could be used,
    but always str2entry_dupcheck() is called.  The reason is that
    id2entry() sets the flag SLAPI_STR2ENTRY_NO_ENTRYDN and this
    flag is not contained in the set of flags known to be handled
    by str2entry_fast() although it does have code for this flag.
    
    Fix Description: This patch is adding flags SLAPI_STR2ENTRY_
    NO_ENTRYDN and SLAPI_STR2ENTRY_DN_NORMALIZED to the local
    macro SLAPI_STRENTRY_FLAGS_HANDLED_IN_SLAPI_STR2ENTRY,
    which is used to determine the string formatted entry can be
    processed by str2entry_fast or not.  Also, this patch defines
    a macro str2entry_can_use_fast to increase the code readability.