New DEBUG facility - modified DEBUG
    
    https://fedorahosted.org/sssd/ticket/925
    
    Modified: DEBUG() macro to work with new levels
    
    There are several new macros in util/util.h:
    
    - DEBUG_MSG(level, function, message) which will format the debug message
      like "(time) [prg_name] [function] (level): message\n"
    
    - DEBUG_IS_SET(level) that you should use to check if the level is allowed
      to be logged
      You can use it like: if (DEBUG_IS_SET(SSSDBG_TRACE_LIBS)) {...}