Fixed critical bug on 64 bit systems.
Cleanups


BUILD/compile-solaris-sparc-purify:
  Added --debug option.
sql/log_event.cc:
  Added DBUG_xxx statements.
  Cleanup
sql/opt_range.h:
  Dummy fix to remove warnings in purify
sql/repl_failsafe.cc:
  Cleanup
sql/slave.cc:
  Added DBUG statements to be able to find bugs.
  Optimized code.
  Fixed critical bug on 64 bit systems.
sql/sql_repl.cc:
  Added DBUG_xx statements.