Ticket #48252 - db2index creates index entry from deleted records
    
    Bug Description: When an entry is deleted, its indexed attribute values
    are also removed from each index file.  But if the entry is turned to be
    a tombstone entry, reindexing adds the removed attribute value back to
    the index file.
    
    Fix Description: In the reindexing function ldbm_back_ldbm2index, if the
    entry is a tombstone entry, it skips reindexing operation unless the target
    attribute is entryrdn or objectclass.  If it is reindexing the objectclass,
    it indexes just for the key "=nstombstone".
    
    https://fedorahosted.org/389/ticket/48252
    
    Reviewed by mreynolds@redhat.com and rmeggins@redhat.com (Thank you, Mark and Rich!!)
    
    (cherry picked from commit ca4d38dff3bd820af2bf60c9bcc82fd64aac2556)
    (cherry picked from commit 86b96278871d8b08f7c6a75379935c2183f6668f)
    (cherry picked from commit ef0a2954cba650364ba4c48038d69731ebe19387)
    
    Note: This patch contains the memory leak fixes.
    (commit 4277f2ba4f1bb24efc771ea0fa02354654db255c)
    (commit 8c9c2fcb14843089a7b5abd02ab1738249b64516)
    (commit f10e2e633ad9c55bc2b42bceef3f9635d7ac5b7c)
    
    (cherry picked from commit 6a1f2f0977ef04dc06b13c7efa3fd35e8f858eab)