Ticket 48978 - Fix logging format errors and replace LDAP_DEBUG
    
    Description:  This patch fixes a few format issues where the plugin name was
                  not used for the subsystem.  Also replaced the LDAP_DEBUG flag
                  with a more appropriate name.
    
                  Also removed the logging macro from slapi-plugin.h
    
    https://fedorahosted.org/389/ticket/48978
    
    Reviewed by: wibrown & nhosoi (Thanks!!)