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
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.