o Changed the multilog API a bit (I warned you)

 o Changed the multilog API a bit (I warned you)
   - multilog_add_type, multilog_del_type, multilog_custom, and
     multilog_init_verbose all have different arguments.
   - Primary change is that caller only passes in config info, and the
     lib keeps track of state internally.  No more exporting of
     'struct log_data'.
   - Custom callers now only get the custom data pointer passed into their
     log fxn (that is set with multilog_custom)
   - Added basic README that describes libmultilog