Now the I/O thread (in flush_master_info()) flushes the relay log to disk
after reading every event. Slower but provides additionnal safety in case
of brutal crash.
I had to make the flush optional (i.e. add a if(some_bool_argument) in the function)
because sometimes flush_master_info() is called when there is no usable
relay log (the relay log's IO_CACHE is not initialized so can't be flushed).


mysql-test/r/rpl_loaddata_rule_m.result:
  avoid a harmless error in the .err file; we don't need a slave in this test
  (even though it's called 'rpl' because it's testing binlog-ignore-db).
mysql-test/t/rpl_loaddata_rule_m.test:
  result update
sql/repl_failsafe.cc:
  update call to flush_master_info() according to new prototype.
sql/slave.cc:
  - Now the I/O thread (in flush_master_info()) flushes the relay log to disk
  after reading every event. Slower but provides additionnal safety in case
  of brutal crash.
  I had to make the flush optional (i.e. add a if(some_bool_argument) in the function)
  because sometimes flush_master_info() is called when there is no usable
  relay log (the relay log's IO_CACHE is not initialized so can't be flushed).
  - Update version in message.
  - Remove warning about bug as it's not true anymore (since this changeset).
sql/slave.h:
  new prototype
sql/sql_repl.cc:
  update call to flush_master_info() according to new prototype.