now we'll have something like this :
030308 18:46:58  Slave I/O thread: connected to master 'gb@localhost:3306',  replication started in log 'FIRST' at position 4
030308 18:46:58  While trying to obtain the list of slaves from the master 'localhost:3306', user 'gb' got the following error: 'Access denied. You need the REPLICATION SLAVE privilege for this operation'
030308 18:46:58  Slave I/O thread exiting, read up to log 'FIRST', position 4
instead of "Error updating slave list: Query error".
This fixes bug #80.


sql/repl_failsafe.cc:
  Clearer error message when one forgot to grant REPLICATION SLAVE
sql/repl_failsafe.h:
  Clearer error message when one forgot to grant REPLICATION SLAVE
sql/slave.cc:
  Updated for new syntax of update_slave_list